You can also obtain most apps via Accrescent, F-Droid or Aurora Store without registering with Google or without Google services.
Attention! F-Droid and Aurora offer you more privacy but also less app security (weaker app reviewing, no integrity check, some apps could be malicious). Therefore, only use these app stores if you are familiar with the risks.
Always prefer Accrescent if you can. Although they offer fewer apps, they are verified and have a high level of security.