A different take: Google bases pretty much all of their decisions on data collected through analytics, feedback reports, and user testing. If they make a change, it's likely because the data they have showed that it was a good change to make. If you don't like how something is implemented, I implore you to send feedback directly to Google about it.
For general Pixel stuff you can do this through Settings > About phone > Send feedback about this device. Most Google apps (including the Phone one) also have an option at Menu > Help & feedback > Send feedback. I'd recommend using both of these options to make sure that your concerns are seen by the appropriate team.
That said, I personally prefer not being able to answer the phone with a single tap. That makes it way too easy for me to accidentally answer a call as I'm pulling my phone out of my pocket to see who's bothering me. A swipe is a much more deliberate gesture and helps me to avoid those uncomfortable calls.