Yes, the official explanation that Lee Harvey Oswald was, on his own, responsible for murdering President Kennedy is overwhelmingly accepted as correct. It has largely held up to intense scrutiny over the past 50 years and there is no substantial evidence toward any other explanation.

As I mentioned in my older post linked elsewhere, one of the reasons why there was so much criticism of the official explanation after the fact is that the investigation was not handled well. This resulted in a lot of seemingly contradictory and unexplained information that opened the door to questioning the overall conclusion as a whole.

It was also complicated by the fact that Oswald himself was a somewhat shady and shifty character--he defected to the Soviet Union at one point, he spent a summer in New Orleans away from his family passing out pro-Castro leaflets, things like that. The oddities and gaps in his background made it easy for people to project things onto him--"he was a soviet spy!" for example or "he was really a covert CIA double agent!"

At the end of the day however, the vast majority of the physical evidence and the background evidence points to the same conclusion: Oswald was a troubled man who had become disillusioned with his worldview and lashed out in a way that would put his name in the history books forever.

While we wait for someone to respond specifically to this question, here's an older post about the JFK assassination. where u/maestro876 answered u/Goodguystalker. Thanks!