This is a growing pattern in hosting like Netlify and headless CMSs like Sanity. Their free model is "generous" and then if you go production and start to have overages you get billed exorbitantly for bandwidth and API requests. It is essentially a trap. Once you hit those limits you have very little negotiating power when you hit the "call us for pricing" level and you get outrageous quotes. It costs them very little to run these services so if they can net some minnows that become whales, that is almost pure profit.