That would effectively make it impossible for single/small dev teams to justify making apps for the Play store.
And I don't see why filter paid apps would solve anything. The aversion of the average Play store user to spending money on anything is in part the reason we are in this mess.
12 continuous years working as an Android developer and I've never bothered to personally release an app on the Play store. There is nothing to be gained from it except needing to support it without any hope of making back the cost of developing it.
Ads, I however agree with, are the bane of our time. Except, due to the aversion to paying for apps, it has become the only way small dev teams can make a living.
The change needs to happen on the consumer side for this one. Buy the apps that you enjoy using.