There seems to be a whole market of Google Play developer accounts and apps for sale, developers like myself regularly get emailed by scammy companies offering to buy the account or to publish an app, and malware is regularly found on Google Play[0]. There's no reason to believe that bad actors would be stopped by install restrictions if their scam is effective enough to overcome the financial hurdles

[0] https://www.bleepingcomputer.com/news/security/malicious-and...