Not sure what to say. The last few visits with FP+ have been in the summer months when crowds were high. (Not peak spring break or Christmas crowds mind you, but above average crowd level).
It feels like we used a totally different FP+ system than you, even though that can't be the case. Sorry you have such a lousy time with it. It may have to do with you following TP's schedule. Big fan here of Touring plans by the way. Love the Lines app, the room selector, reservation finder, articles, etc... I've subscribed annually since 2010 but have never used their premade or custom tours.
Just like with G+, FP+ was most effective for MK. At MK we fastpassed all day long and rarely went standby. We'd regularly see people in a 20 minute line for say, It's a Small World, and I'd look on the app and see that I could FP it immediately. When you did that regularly that ends up saving a LOT of time in a day for other things. Headliners were not hard to find either. 7DMT? Yes, very hard to get day of, but even that we've done.
At EP we could regularly get Soarin day of. At AK we could get anything other than FOP day of. At HS (this was before Galaxies Edge) we could get anything day of with the exception of SDD.
We looked at the app much more than "a few times each day" though. We put our time/effort into it and it paid off big every time.
Dan