Which Android though? AOSP doesn't have ads. But Samsung phones are full of ads for their own and other's services (McAfee VPN, McAfee security scan, OneDrive, etc.). I heard that Chinese phones are similar. Even Pixel pushes Google One in places.
The primary exceptions are GrapheneOS and Lineage, but it's not like people can buy a phone with them in the store (yet).
I have used several models of Sony Compact phones, until Sony discontinued that line of products, then ASUS phones.
No ads on any of those, and moreover I never had and still do not have any Google account.
The only problem that I had for not having a Google account was that one of the banks with which I was working terminated their on-line banking and replaced it with a smartphone app. That would not have been a problem, except that they refused to provide the app directly for download, but only from the Google store, which cannot be used without a Google account.
The primary exceptions are GrapheneOS and Lineage, but it's not like people can buy a phone with them in the store (yet).