Is it possible to allow sideloading and keep users safe?

There are millions of homeless or otherwise struggling people all around the world, who would let anyone to use their identity for a small compensation. I don't really see how this requirement to register in Google will help with app security. So the malware will be signed with John Smith living under a bridge, now what?

Unfortunately, the reality is that often their identity is not actually "good enough" to perform these actions. For example, many of these people don't have an address/bank account/email.