I have 15-20 domains with Google so it’ll be a pain to manage something else. Even if I can’t trust Google’s privacy or product continuity, I do trust Google’s security and have multi factor enabled already, so having my domains protected by them is a great thing. I’m pretty much always logged into my Google account on my PC so it’s one fewer account to manage.

Squarespace is probably fine, but I bought my first domains through a web builder and web host years ago and they slowly raised prices and reduced features until I had to leave them and moved to Google.