Id go so far as to say SaaS in general. Small startups are paying $5000/month to send emails and we’ve come to the point where inboxes are monopolized and if you don’t pay up to a cloud provider your emails end up in spam.
Take this and repeat for everything. Monopolize, ratchet up the costs, profit.
This goes back to around 2000. Snake hunting in the Everglades middle of the night, my friend and I saw a black panther. I know, I know, impossible, Florida doesn’t have them etc etc etc. we both saw it clear as in a zoo in the floodlights of his truck. 100% big cat, 100% black.