There is a lot to unpack here. First, you should know that Bobby Fischer suffered from mental illness from a very early age. I did a 2.5 hour presentation on Fischer's biography, including discussion of mental illness, if you're interested. This bears on the "lone wolf" characterization which I will address later. Second, you should know that Fischer was undoubtedly the strongest chess player in the world in the years before the world championship, but he wasn't playing. He didn't feel like he was getting paid enough, felt like others were colluding against him (and he was partly right), etc.

He was convinced to play in the qualification to become the official challenger in 1970, and began a streak of play which has seen no equal before or after. He won the interzonal tournament by a large margin, ending with 7 straight victories (no losses or draws). He then played Marc Taimanov, a strong Russian GM, in the quarterfinals, and crushed him 6-0 with no draws. The beatdown was so bad the Soviets would yank Taimanov's chess stipend and bar him from international competition, essentially ending his career. In the semifinals,Fischer played Bent Larson, widely considered the second-best Westerner to Fischer. Fischer beat him 6-0 with no draws, too. The finals were a bit harder, but after settling his nerves, Fischer beat Tigran Petrosian, the former World Champion, four straight games to close out their series.

Once he earned a spot in the World Championship, Fischer tried to negotiate and renegotiate everything about the series, from the location (switched several times before ending up in Reykjavik) to the prize purse (increased to the unheard of $125,000). And after all that, he still refused to go until a wealthy financier doubled the prize purse out of his own wallet. So there was lots of mystery and drama about whether (and how) Fischer would participate in the match, and this continued through the match.

Spassky had a team. For 30+ years, since Mikhail Botvinnik had put Soviet chess on the map, the Soviets took it very seriously, with players putting their own interests aside in the name of advancing Soviet chess. Among other things, this meant some of the collusion I discussed earlier, where Soviet GMs would make quick draws against one another in tournaments to save their strength against Westerners like Fischer. Spassky had three top Soviet GMs with him to help prepare openings, analyze matches, etc. Fischer had Bill Lombardy, who was a GM (a weak one) and a Catholic Priest. Lombardy was there mostly to keep Fischer calm and focused, as his ability in chess paled in comparison to Fischer. Fischer had a lawyer accompany him (Paul Marshall) and a representative from the U.S. Chess Federation (Fred Kramer), but Fischer spent most of his time alone.

Fischer was paranoid. Part of this was likely mental illness, but part of it was probably warranted. The FBI had spied on Fischer's mom (a Communist sympathizer) and Fischer for years. He believed that the Soviets would try to kill him or otherwise seek to incapacitate him. I'm not aware of any effort on their part to do so, but it would not surprise me. After losing this match and signaling a willingness to defect to the West, Boris Spassky suffered under the hands of the KGB, who, among other things, tried to get him to contract a sexually-transmitted disease by infecting his girlfriend's undergarments. Fischer would also, due to his religious beliefs, isolate himself (notably on weekends). So Fischer trusted almost no one, and his illness would negatively impact his participation in this match (consider the negotiation around lights and cameras) and effectively ensure this was his last serious match ever (because he refused to ever compete again until the 1990s when a lucrative proposal pulled him briefly out of retirement).

Now you ask if the match was widely regarded. For a chess match, the coverage in the U.S. was unprecedented. Public Broadcasting Services (PBS) aired the matches live on television. Of course, without cameras in Reykjavik, the moves were related to chess master Shelby Lyman, who displayed them on big boards and spent up to 5 hours providing commentary on each game (source).

There are many, many books on Fischer and this match, but here are a few I would recommend:

Endgame: Bobby Fischer's Remarkable Rise and Fall – from America's Brightest Prodigy to the Edge of Madness by Frank Brady. Start with this one--it's by far the best biography of Fischer, from someone who knew him personally.

Bobby Fischer Goes to War: How the Soviets Lost the Most Extraordinary Chess Match of All Time by David Edmonds. This places chess into the broader context of the cultural Cold War.

A Psychobiography of Bobby Fischer by Dr. Joseph G. Ponterotto. This is who I defer to for psychiatric diagnosis. Ponterotto also examines Fischer's early history with psychiatrists, including a racy accusation that the chess club of New York avoided recommending therapy for a young Fischer in order not to blunt his potential.

The KGB Plays Chess: The Soviet Secret Police and the Fight for the World Chess Crown by Boris Gulko and other GMs who defected from the Soviet Union. If you want a story about the KGB sprinkling Chlamydia bacteria on Spassky's girlfriend's undergarments, this is your book.

Bonus--The current world champion is the Norwegian Magnus Carlsen. Carlsen rose to prominence at an early age, and has dominated chess for several years now. But unlike Fischer, he seems well adjusted and even in tune with new media, including some live streaming.