Note what other people in this thread are saying.
Sorry, but being a developer I can tell when players are just repeating half-truths they read online.
There's no reason why strategies that work in any other kind of computer science shouldn't work in gaming.
In fact, it sounds like you think a 'ban' is something bad to these players or will stop them. If it did, I'd probably be enjoying Rust still.
The difference between an attack costing $0.00 and $$0.01 is enough to reduce attack volume by orders of magnitude.
Even just costing the attacker 30 seconds is enough to have a massive effect, which is why captchas exist.
Game keys tend to be in the $1 - $5 range, which makes bans an extremely useful tool.
The affordable Sony Xperia 10 series is really good. My new Xperia runs circles around my OG Pixel, costs basically nothing, is waterproof, has upgradable storage and a headphone jack, and besides Apple, Google and Intel, Sony is the only manufacturer that actually has working bluetooth.