When you create a Gmail account Gmail will ask you to enter your date of birth, phone number, and other details, but merging a phone number is your own choice, you can tap the next button you don’t want to merge your number with Gmail. And, there are other email services where you can create a gmail account without a phone number. You can visit our given article if you want to create an email without phone number.
Article: https://getassist.net/email-services-dont-ask-for-phone-verification/