Not just one -- servers in 175 (and growing) locations spread around the world, and the app will always use the closest one to you. That's arguably a lot more important that what protocol it uses, and is not something you could easily DIY.
I'd say that even the known unknown that ips and networks change routinely should make it a headache to maintain.
In this case, I agree that a single VPS is usually enough for most but never underestimate the market power of making things simpler and faster.
(Not implying anything, just providing a discussion point.)
Once you get your script to work, you’d have to wait minutes for the VPN to spin up in a new region.
Check out algo: https://github.com/trailofbits/algo
I think you could bake your configuration into a custom image, so it would be fast to get a VM started (about 30 secs on GCE, not sure about EC2).
If you use stopped instances, it's even faster.
(I work at GCP so know more about GCE than EC2)
Even if you change residences, you'll typically be in the same state. Even if you change states, you can just set it up again in, what, super conservatively, under an hour (you've already done it once so fewer missteps).
I was lucky to find small paid VPN provider, that doesn't do marketing, pay for referral and stuff, and I'm sticking to it.
I'd disagree. Many VPN protocols suck even if the gateway is in-house. I guess there's a reason they introduced that with Wireguard specifically.