I've been playing it lately and I really don't like the physics. I feel like everything understeers a lot. Like I take the same corner in a different game and I'll get through it but in this game, it'll understeer into the grass.
That's one way to look at it. The other way is if you're understeering you're going too fast for the tyres and the conditions. The tyre and tarmac grip levels may simply not be as high as you're used to. The grip levels are certainly lower than what you might experience in "different" games.
If you're finding understeer to be an ongoing issue that you want to do something about (and it is in some cars) then you can consider tuning. Things to try are:
-More front aero/less rear aero
-Less front ride height/more rear ride height
-Softer front anti-roll bars/harder rear anti-roll bars
-Softer front springs/harder rear springs
-Lower front tyre pressures/higher rear tyre pressures
These are not the only things, but they're simple. Some may not be applicable or may not work well on some cars, but if you take your time and experiment you'll find which of them is right for you. Once you get one car right for you, you'll probably be able to make similar adjustments for other cars.
The brakes are also aren't as strong as other games.
There's some pretty big differences between brakes depending on the car and the tyres it has fitted. Much more so than in "different" games. Particularly in things like the pony cars, some brake fairly well and others you'd be as well holding an umbrella out the window (I'm looking at you, Mach 1).
Personally, I find the physics to be fun, engaging and rewarding to master. But if you're coming from certain other games then you're going to find it very, very different. If you can give yourself time to adapt you'll probably come to like it, but if you're not finding it fun then maybe just leave it. You can always come back another time and try it if you want.