Tons has changed, we just have come full circle
Strict penalties were introduced with 10 sec penalties for the slightest contact. It cleaned up racing fast, yet then the fast people started complaining that rubbing is racing and they have to be able to drive bumper to bumper or else it's no fun. Plus FIA races with all flashing penalty signs were ugly to watch as well as the constant penalty serving on the racing line turning it into a circus.
So since halfway 2018 penalties got less severe and turned off altogether for minor contacts, track limits became more and more loose with smaller penalties (the days of 10 sec for nicking a bit of kerb on Monza!) as well as less sensitive walls, and it became easier to scrub penalties without slowing down much. So here we are, back in 2017.
Other changes include lapped cars are now ghosted as well as penalty serving cars with the actual time displayed and communicated between clients. SR Down arrows have disappeared and re-appeared (SR was always deducted just not shown) Report function and disqualification have been added. DR resets have been fixed (No more reset upwards to 50K, exploit that was used a lot) SR budget per track has been tweaked as well as SR deductions for contacts. Matchmaking has been tweaked to increase SR range selection to put more people of similar pace together.
Yet it turns out, most people won't change their behavior no matter what PD tries.