One of the reason I can think of is, not knowing how to set the fees. These days almost all wallet software have feature to adjust fees. I use Electrum always and most of the time the default fees are higher than the minimal fees which is fine to get the next block so knowing to adjust fees is very important for anyone who is in bitcoin.

Another reason could be, not aware of what fees to set but in this particular case it does not seem the suggestion from the wallet software was followed too. 653 sat/vB seems too high to suggest. The sender could be testing something. Or he missed type the fees field when he was trying to adjust the fees.

Usually I noticed gambling companies do not care about fees. They have fixed fees set for withdrawals and sometimes it's too high than the required fees for a block.