Three factors that influence the speed of cashouts are:
Verification procedure
Selected payment method
Claimed amounts of wins
Verification is a KYC procedure that may or may not be implemented by an online operator depending on its obligations to the licensor. It usually takes between 24 to 72 hours and applies to first-time-withdrawers, as well as to those who won jackpot sums.
In terms of payment methods, the fastest way to claim wins is to e-wallets, and it will take between 24 hours to two workdays. An even faster way may be to claim wins to a crypto wallet. Such withdrawals can even be instant (rarely) or take up to 24 hours (a more realistic outcome).
Finally, the bigger the amount that a player withdraws, the longer it takes an online operator to process the withdrawal. So, plan accordingly.