My main area of specialty (ancient Greece) is about as far away from the twentieth-century United States as it is possible to be, but I'm going to answer this question nonetheless because I feel informed enough to answer.

Your perception of the 1920s in the U.S. seems to be influenced primarily by contemporary (i.e., twenty-first-century) fixation specifically on the rebellious, predominantly urban subcultures of that era, especially the jazz, flapper, and youth subcultures, and seems to completely ignore the wider culture of the time.

For instance, you specifically mention "drinking" as an important part of 1920s popular culture, but you seem to be forgetting that the production, importation, transportation, and sale of alcohol was illegal throughout the entire United States under Prohibition from 1920 to 1933. It's true that many people in the U.S. certainly drank alcohol during the 1920s and drinking was central to some subcultures of that time, but, because a person could literally be arrested for transporting and/or selling alcohol, this drinking was usually clandestine.

You also mention that "homosexuality" was "slightly more acceptable" in the 1920s than it was in previous decades, which is arguably true enough, at least in some circles, but you ignore the fact that same-gender sexual relations were still widely seen as taboo, sinful, and contrary to nature. Something being "more acceptable" than before does not automatically equate to everyone being totally ok with it. Similar statements can be made about women in the '20s attending college and working jobs for income outside the home; these things became more acceptable, relatively speaking, in the '20s, but were far from universally accepted.

(Just for clarification, in no era of U.S. history have women ever been discouraged from "working" in the sense of performing labor; women in the U.S. have always been expected to perform labor around the house, including, in particular, cooking all the meals, washing all the dishes, doing all the laundry, and doing most or all of the work in raising children. The repressive, patriarchal "separate spheres" ideology does not hold that men are supposed to work and women aren't, but rather that men are supposed to work outside the home and earn income to support the household while women are supposed to do work around the house.)

Meanwhile, your perception of the 1950s fixates on the contemporary, twenty-first-century stereotype of the wider culture of that era as stiff and conformist. It completely ignores the existence of subcultures of that era similar to those of the 1920s, such as the anti-conformist Beatnik youth subculture, which was closely associated with drug use, jazz music, long hair, and esotericism and which eventually fed into the hippie movement of the 1960s and '70s.

Most of what you say about the 1950s would be equally true of the '20s, if you were to simply ignore the rebellious and anti-conformist subcultures of that era entirely in the same way that you do with regard to the '50s. In the '20s, many or even most people still viewed the nuclear family as ideal (as, I should note, many people still view it even today) and, although some women in that era did attend college and work jobs for money outside the home, they were still often discouraged from doing so.

Regarding gay rights, it is true that, in some ways, society did become more hostile to same-gender-attracted people in the 1950s, primarily because, in the context of the Cold War and the Red Scare, many people believed that the Soviet Union could blackmail same-gender-attracted people into spying for them by discovering and threatening to reveal information about their sexual orientations and that same-gender-attracted people therefore posed a national security threat simply by existing.

In 1953, President Dwight D. Eisenhower signed Executive Order 10450, which effectively designated anyone suspected of being sexually attracted to persons of the same gender as a security risk and banned all such persons from holding jobs working for the government. As a result of the order, over 5,000 federal employees were fired for being suspected "homosexuals."

At the same time, though, the 1950s is when the homophile movement and the first prominent gay rights activist organizations in the U.S. began to emerge. The Mattachine Society, which sought to protect and advance the rights of same-gender-attracted men, was founded in 1950, and the Daughters of Bilitis (DOB), which sought to protect and advance the rights of same-gender-attracted women, was founded in 1955.

Admittedly, these early gay rights organizations founded in the 1950s tended to be fairly cautious and pro-assimilationist in their activism and tended to discourage overt gender-nonconformity, emphasizing respectability politics instead. As a result, more radical activists from the late 1960s onward tended to spurn them and their methods. Nonetheless, they still occupy an important place in twentieth-century queer history and they helped to pave the way for the modern queer rights movement, which really took off after the Stonewall uprising of June 28 – July 3, 1969.

You also mention "smoking" as a facet of mainstream pop culture of the 1920s, but smoking tobacco wasn't illegal or widely taboo in the U.S. in the 1920s or 1950s. In fact, although some people and groups (including, most notably, some of the more pietistic Protestant groups that also supported Prohibition) have long disapproved of tobacco smoking, it has only been in more recent decades (really only since the 1980s) that the general public has come to recognize the dangers of tobacco smoking and that western governments have really done much to discourage it.

Finally, since you mention the Civil Rights Movement, it's worth noting that, by nearly every possible measure, the 1950s was in general a better and safer time to be a person of color in the U.S. than the 1920s. Some historians have actually considered the 1920s, or at least the early '20s, to be part of a period of U.S. history known as the "nadir of American race relations," in which open white supremacy and Jim Crow laws reigned supreme across the American South, the revived Ku Klux Klan was at the pinnacle of its power and influence, and lynchings were normalized and widespread.

The infamous Tulsa race massacre, which has been described as the worst single incident of illegal racist violence in U.S. history, took place in 1921. Even in the North, by the mid-1920s, the Klan had such a firm control over the state government in Indiana that D. C. Stephenson, the Grand Dragon of the Indiana Klan, famously boasted: "I am the law in Indiana." (The Klan's influence, both in Indiana and nationwide, eventually waned over the course of the latter half of the 1920s and into the 1930s.)