Surprisingly no, you can use an Android phone without an account. Though you cannot install any applications from the Play Store, tbf I'll count that almost as a positive.

You can do that just fine. Huge swaths of people just use the Amazon app store or the Samsung One. F-Droid is also an option if you don't want to make any accounts.

you can use an iphone without an apple id.

- you have to dodge dark patterns to get through setup without one

- you can't install software

I've mostly just used LineageOS for several years now, but I believe the first time setup pushes you to sign in to a Google account, but you can easily skip it. If you do sign in, it's sticky/permanent and I think may require a reinstall to get back out of it.