Update: My car is a 2019 VW e-Golf SEL with wired CarPlay. Historically (prior to the 17.2.1 update) CarPlay wouldn't work 5% of the time. I'd plug in my iPhone, CarPlay wouldn't work, but the phone would charge and give me some other indication that it was connected via USB. This was the case for the almost three years I've had the car, using MFI cables and the latest iPhone each year with current iOS updates. CarPlay wouldn't work, but later in the day it would start working again after the car had been off for awhile, but without any further involvement from me. It would just start working as it should.
This new 17.2.1 update was different. No matter what I tried, it wouldn't work with my 15 Pro on 17.2.1. Other iPhones not on 17.2.1 would work immediately.
After deleting my CarPlay profile on my same 15 Pro with 17.2.1 and after a week of testing, I'm happy to report that CarPlay is working again, aside from the very first time I connected after deleting my car's profile from my phone. But, since then, it is working. I know this hasn't been a fix for everyone, but it's worth a try if you haven't done that. Hopefully Apple will recognize this issue and fix it in a future update.