I've played them a bit, and on paper I think they do a lot of things right. the way they force you to practice on a track before a race makes sure you actually know how to tackle each track, and the AI feels much better to race against than other sim games I've tried. And the driving model also seems fine.
But I just find them so exhausting to play. Between practice, qualifying, and lengthy races, each event takes at least an hour or two, or even more if you want to play with longer race times (which I feel like I should because shorter races don't feel right to me). And that's a huge time commitment. Granted you don't have to do all of that in a single play session, but if I don't then I'll forget what I've learned in practice by the time I play qualifications and the actual race.
I think that's how I feel. Like short race doesn't feel right and I went with Alfa Romeo so it's kind of hard to be top dog so quickly, so it almost doesn't feel satisfying either