A payout can be quick and still arrive short. Five deductions are worth checking before the first deposit, because they are all in the cashier or the terms.
Network fees. On crypto rails you pay the chain, and the size depends on the chain and how busy it is. On slow, expensive chains this is a real cost. On cheap chains it is close to noise.
Internal fees. Some operators charge nothing beyond the network cost, some charge a flat amount per withdrawal, some charge after a set number of free payouts per month. Thunderpick is reported to charge no internal fee beyond network costs, alongside a reported monthly withdrawal limit of EUR 500,000, both from a single unverified source.
Minimum withdrawal amounts. A flat fee is a percentage in disguise once you divide it by the smallest payout allowed. A $5 fee on a $50 minimum is 10%.
Conversion spreads. If the operator converts your deposit into a house unit on arrival and back on withdrawal, the difference between their rate and the market rate is charged on both legs and never appears as a fee.
Requirements attached to the deposit itself. BetFury's terms, for example, place a wagering requirement on fiat deposits of two times for casino play and three times for sports, before any bonus is involved. A deposit that has to be turned over once before it can leave is not a free deposit, and the cost of that turnover is the house edge of whatever you play it on.
Caps and instalments matter at the top end. A monthly limit or a rule paying large wins in instalments decides how long a big result takes to reach you, and no amount of fast processing changes it. /responsible-gambling covers the limits worth setting before any of this becomes relevant.