Which one matters most to you, is it speed or just getting your winnings, no matter how long you have to wait?
Conditionally, if it's a large amount, then I don't mind the speed as long as the delivery time is reasonable. If it becomes 3 days - 1 week, that's unreasonable, I will make a complaint even if they will pay for it. Then, if it's a small amount, I hope it can be processed quickly, some platforms that I use & have fast withdrawals are Rollbit & Stake.com.
Reputable casino usually process withdrawal quickly regardless the amount at least on my case. My withdrawal of 100$ is same speed when I withdraw a balance of 5000$ and above.
I don’t know what’s the scenario on 10K and above withdrawal but based on my experience it’s all the same instant unless your account show sign that will trigger security alert of the casino.
I have some whale friend that can withdraw almost instantly on many reputable casino.