Yeah I have this problem too. I use the reading list option, I try and add things that are rarely requested so that, if I'm on a load of waiting lists/a book becomes available I'm not in the mood for, I can return it and check my reading list for something available now. I also sometimes will return a book and then re-request it, putting myself to the back of the queue in case I will want it when it next becomes available.
It has been frustrating me recently, because I've been reading a lot more. So I've started using the actual library itself for physical copies. When I request a paper book I seem to get it much quicker (was on the waiting list for the Mick Herron on BorrowBox for a year, and current waiting list for it goes up to 2027. However there are loads of paper copies of various books of his and I've read 4 in the last month).