A UKGC licence is the baseline, not the whole story. Look for clear RTP...

https://www.bookmarkidea.win/good-uk-slot-sites-stand-out-in-the-details-not-bonuses-ukgc-status-is-the

A UKGC licence is the baseline, not the whole story. Look for clear RTP information for each slot, straightforward withdrawal terms, and realistic processing times