I did manage to get the battery swapped in my Pixel 6a. A local phone repair shop agreed to try even though they don't normally do Pixels (In Greece, anything that's not Xiaomi / Samsung / Apple is exotic). The previous (original) battery had become catastrophic with Google's software updates, it would barely last an hour of screen time, even though I was very careful with it from day 1, avoiding fast charges and full charges.
I miss the time when you could swap phone batteries with no tools.