And how much grift happens through Android side loading? (BTW, I hate that weasel word used to vilify a perfectly reasonable activity.) Practically all grift on Android happens through apps on the Play Store. People who know how to 'side load' are also usually careful and smart enough to think about what they're putting in. That's not a useful target for grifts either.
As somebody put it, Google goes after others without cleaning their own house first. It's just abuse of power at this point.
F-Droid at least does a quick review to make sure there's nothing malicious in the app before adding it. Since we know Google does something similar and there is still malware on the Play Store one might reasonably conclude that Google doesn't actually care about malware.
Now, it might be a problem of vetting at scale or malware being really subtle, but if that's the case Google should focus on improving their process before locking down Android for "security".
You can still install any ROM you want. Not having Play Store has some downsides, but those trades offs should be familiar to a free software enthusiast.
As somebody put it, Google goes after others without cleaning their own house first. It's just abuse of power at this point.