[NorwegianDude]

To be fair, Gmail asks for a phone number, but you dont have to add one.

[cyphar]

This might depend on the country you're in, but I'm quite certain I've gotten locked out of the signup flow in the past when I refused to provide a phone number.

[wkat4242]

It depends what you do it from. If you do it from an android device you don't have to. If you do it from the web you do.