Your take is too hot considering a lot of real life professional racers use iRacing for training. iRacing is a sim, you like it or not.
First of all, I am not a fan of iRacing nor an advocate of it. I simply prefer a sim over an arcade, period. I feel insulted when games like Gran Turismo advertise themselves as "the real driving simulator" when in reality the game is a hilarious arcade with unrealistic grip and car performances.
IndyCar and IMSA drivers for example, do use iRacing for training. Even F1 three time world champion Max Verstappen and F1 ace Lando Norris are occasionally seen playing on iRacing, mostly Max due to his involvement with Team Redline.
When many professional racers uses it for training, certainly the physics are great and realistic.
Max himself has expressed preference for games like rFactor 2 and iRacing due to them being closer to the real deal. During pandemic he even avoided as much as possible the events from F1 using the Codemasters game saying the game is literally garbage - and I can agree with him that the game really is.
Toxic communities, all games around the world have. The internet is full of toxic people, regardless of their games or social network. Retro gaming emulators communities are much more toxic than that. That problem is not exclusive to iRacing. If this is a reason for you not to play it, man, I have bad news for you... you probably won't like to play any online game at all, because all them have toxic traits. Even Counter-Strike clans have a toxic community.
"Since they take the things too seriously"
Mate, its a sim. You want fun play an arcade. A sim is serious gaming, realistic physics, car tyre grips, competitive behavior. You have to take it seriously to compete.
Gran Turismo, Forza and all the F1 games made by Codemasters/EA are Arcades. I refuse to play them. They're a joke. But good enough for kids to enjoy their afternoon on their consoles, I suppose.
I play racing games since I was 7 yrs old (1989) and had a copy of ACCOLADE GRAND PRIX and WORLD CIRCUIT; I did play iRacing and rFactor (1 & 2) in my "short" tenure as a competitive online simracer (in 2000's and 2010's) in the past and I have tested current iterations of these games as well; you can't make an opinion and a judgement based solely on the videos you have watched. You have to try the games and get their feeling to make a well reasoned opinion.
I also did race real life karting events, so I know a little about tyre grip and handling. I assume most of us did, even for simple go-karting fun.
Hope I did not went too harsh on you but this is just the way I am - strongly direct and straight to the point.