I want to add that, like you, I’ve become a big fan of restricting the numbers of ways to do something.
IMO, It’s more time wasted choosing, more time wasted reviewing, and makes it easier to overlook errors. I want more opinionated languages and frameworks.
Easiest solution IMO if you’re already using CloudFlare, even the free version: you can filter out certain countries. Otherwise, there’s probably other alternatives, even open source ones. Good terms to search for with your cloud provider or self hosted software may be middlewares, firewalls, serverless, edge functions, etc.