Frankly, we have the lovely people who came up with spam (the email type, not the tinned meat) to thank for this. I used to run a private (as in for me, family, and friends) email server. I gave it up because of having to tweak SpamAssassin every day. There were spam filtering services (probably still are) and you guessed it - Google had one of the better ones. So it was pay them for filtering or get already-filtered email for free. If you’ve read about "tragedy of the commons", it’s pretty much those spammers taking advantage of a free-to-them service. If you’re looking for ways that unrestrained capitalism destroys things, it’s this as well.