Most casinos offer a fixed amount I never used other platforms due to their high withdrawal fee.
Good casinos do not charge any withdrawal fee. I have never gambled on a site long term if they charge any fees for payout. I mean, it is well known that online casinos are highly lucrative and if they also ask for money for the payout (admittedly, the fewest users pay out because the fewest win), then that is already an arrogance towards their customers. But it's also up to the users. Avoid such gambling providers and sooner or later they will change your fee policy.
There are some who do shoulder out the withdrawal fees but not all of them but doesnt mean that they arent good ones.Its just they cant really afford to add up into their expense on shouldering the fee into those withdrawal transcations and for those who does then thats one shows about generosity of the site because not all would be offering the same thing.For those places who do have static ones then it wont really be that appealing but for those dynamic which is understandable because of the market condition.It do all varies but i do much prefer on having an option neither you do want to have that
low to high priority type of fees for you to choose on which is a great thing or option for a gambler to have.