But then you need twice the bandwidth (one for egress from your "real" server, once for egress from your "front-end" server), you have a lot more latency, you've created additional points of failure, you need to sync the IPs of your "front-end" to your "real" server to allow it access. Besides that you now need to find reliable hosting from two providers, one for your "real" hosting and one for your "front-end" (using the same provider would just lead to the same issue as in the original post).

Great if it works for you, congrats. But I don't think this solves issues for many people, I doubt it solves an actual issue for you and it's basically the same as using cloudflare/akamai/similar but with a manually setup proxy on a VPS.