Nowhere can this growth of FH5, which is a VERY DIFFERENT game from Forza Motorsport, justify your pessimism towards this game. There are many bugs, many users have moved away (I for one stopped playing “seriously” after what happened to me), it’s still summer and in countries like mine (I live in Italy) spending hours playing in the evening becomes more complicated.
We have to hope that in these months Turn 10 will find the right way to improve the game. The arrival of radar, new replays and a bit more stability may help to win back users.
Don’t forget that Xbox (the platform of reference for this game) sells 1/5 of PlayStation at the moment, so there are already few players anyway, and driving simulators are a niche genre in themselves.
Comparing Forza Horizon 5 and Forza Motorsport just because there are cars is like comparing a specific Roblox map and a Call of Duty map just because there are guns.