I made a Google account without even owning a number a few days ago. Afaik only one of my Google accounts has a phone number and pretty sure that's only because AdSense.
My tinfoil hat theory is that if it doesn't ask for a phone number then it already has a very precise shadow profile about you. Being on linux+firefox+grapheneos compared to windows+chrome+android probably means a lot in that regard.
What do you think?