This is a naive take. Of course these developers already permaban cheaters. Firstly many of these games are free to play so "getting another license" is a non issue. They're doing hardware bans nowadays which are harder to avoid but not impossible.
Half the battle is detection though. If you don't detect cheaters quick enough they ruin enough games that genuine players start getting frustrated and leave. Anti cheats help with this detection.
Probably every anti cheat idea you can think of, in terms of detection, prevention and punishment, has probably already been tried by a large online multiplayer game. It is an extremely difficult problem to solve, a constant arms race.
It's not possible to completely solve this problem with technology.
High level chess players (GMs) can win with just a few bits of information transmitted to them by a cheating accomplice (a cough if it's a critical position to spend extra time on, etc). Similarly, high level gamers only need the slightest of edges to win, and therefore only need the slightest of cheating.
That's why I think trusted user bases are the way to go. My initial ideas were naive, but I think the core idea is solid. If you had to pay $1000 to enter a "trusted club" which uses your hardware fingerprint, and all of your online interactions in a game were guaranteed to be with other people who paid $1000 to be in the club, would that not be a large deterrent to cheating?
That's just elitist though isn't it? These games are enjoyed by players from all over the world, including massive numbers of players in countries with far less average disposable income. Its common in many countries to go to an internet cafe to play these games as they don't own their own hardware even.
It would also massively reduce the number of players. Competitive multiplayer games rely on large active playerbases for fast and fair matchmaking. That's why free to play has become the dominant model for these games. If you have to pay $1000 to play one of these games, they have no chance vs. the competition.
Obviously you can't completely solve this problem, but you can minimize it as much as possible.
Also these sorts of "trusted clubs" do exist for certain games (e.g. FaceIt for CounterStrike) but ultimately it still just relies on anti-cheat to establish that trust.
Money is just one way of establishing "trust clubs". Time is another. For free-to-play games, you could make it so that users are peered with other users who have put in the same amount of time into the system. So if you've gone a whole year without being flagged for cheating in the system, you'll be paired up with other users who have also gone years without being flagged.
If you create a new account, you'll be peered with other new accounts (low trust). Still possible to cheat, but the cost is very high (years of effort to get accepted in the best trust clubs)
CSGO used to have that, more or less. You could play for free but then you were not in the "prime" matchmaking pool. Only by paying, something like 13€, and registering your phone number, which could only be registered once, would you get prime matchmaking. I thought it made quite a bit of sense but I think they scrapped the system in CS2.
It's going on a tangent, but one naive take which continues to amuse me when it comes up is community/third party servers and policing of cheating. As though delegating that responsibility is the goal or that it would scale to handle the size of modern playerbases including the ratio of admins to players to be able to monitor and respond to (alleged) cheaters
But as gaming has grown and become more mainstream, the ratio of enthusiasts who are willing to admin to casual players who don't has changed. Server sizes have changed over time with smaller games like 5v5 becoming way more common.
Half the battle is detection though. If you don't detect cheaters quick enough they ruin enough games that genuine players start getting frustrated and leave. Anti cheats help with this detection.
Probably every anti cheat idea you can think of, in terms of detection, prevention and punishment, has probably already been tried by a large online multiplayer game. It is an extremely difficult problem to solve, a constant arms race.