re: What’s the best “realistic” racing game for PS4?

Not that review scores matter, but F1 is pretty much best reviewed sim racer every year. I haven't played it since 2016, but it was legit then and every year is has supposedly gotten better. And F1 2021 comes out within the next month, so youre in luck if you are wanting the newest release.

If you're on xbox, a few of the older F1s are available on game pass if you want to try it out before buying the new one. I think F1 2018 & 2019 are available to play there

Edit: My bad, just seeing you are looking for PS4.