Google bans new acounts that never used in official playstore before

Use a spare gmail acount that you have also used with playstore

Anonymus logins also get rate limits or get banned

As for alternative

App lounge from /e/ OS uses auroraOSS Gstore api to download from playstore so it's basically like using aurora

Other than that the are Python scripts you could use on termux but those also need a proper gmail account

Same apply to linux/windows programs available

I always used my "normal" google account in Aurora also been using this account with microg since ages Never had an issue I don't care if the account gets banned though.

Maybe appkmirror is the only other "sane" option.