It’s probably just not a good fit for you. Personally it took me maybe an hour to understand how to use the DT (and subsequently the DN/Rytm/A4), the OT definitely took longer. If you’ve used a tracker before the OT is pretty easy though.
For me the worst interface I’ve ever used was the MPC Live. It has dozens of different screen layouts to reach it’s various functions, all of them designed haphazardly with little regard for consistent use of color, shapes and location of virtual knobs. Literally a UI nightmare.