I almost forgot about the original Priceline. It used to offer up to 75% discounts on premium hotel rooms.. if you were willing to take the risk on getting a midrange room for a 10% discount or 20 minute walk from a metro station. The gambling component was fun and you could avoid those risks easily using VPNs. That experience is diluted and now is much less than the value of booking direct and membership points for me.

Booking.com is still good though. I always use it for my first search for accommodation, then reserve using booking.com, or direct with a hotel depending on which one has the best cancellation/change policy. That is still so important due to COVID and frequent flight cancellations.