Everyone from small firms with one to two people all the way to large corps/industry and public bodies and defence. Depending on what they need COTS can work, but a great deal of time you are looking at complete bespoke designs, from the chassis upwards with custom PCB's etc. I've worked with movie studios, game developers, oceanographics, automotive, aerospace and lots more.
Some of these companies work with grants/fixed budgets, and it isn't always for profit, you get universities as an example who will give grants to departments that want a certain spec but have limited funds to do that with, and you also get the start-ups who simply can't afford everything straight away. It's a very diverse market place out there, and most people sadly don't have the first clue just how simple it isn't.
Any who, back on topic. 4xxx, lets see what they are peddling in a couple of hours and how much peoples 3xxx cards are going to fall in value by.
If anyone sells their 3000 series card before knowing the available stock of the 4000 series they are mad and deserve to get burned. Funny during the 3000 announcement that peeps on here panic sold 2080ti cards. Only for them to hold value within the first month of the 3080 release.