I don't think Cura is any worse than other slicer software. I am currently trying to get my head around PrusaSlicer which does all the same things as Cura but not necessarily in the same way. Part of the problem, I think, is that 3D printers are far from being plug and play. Every little nuance of operation can be tweaked in some way. Leading to probably in the region of 500 or so settings that can be changed, some of these make no apparent difference whilst others are in 'crash and burn' territory.
This need for variability is in mainly connected to the variability in medium. No two rolls of filament even from the same maker are identical even if nominally the same material. This needs then a degree of experimentation to find the right temperature, speed, retraction, cooling etc. every time a new roll is loaded. Even then once you have established a good working list of settings, a particularly hot, cold, damp, or windy day may make a difference to the outcome. There are of course other things like wearing nozzles, bearings or indeed a defective STL file to contend with.
I am afraid there is no easy answer to any of this. The main thing with the software is to only alter one thing at a time and when you have achieved what you want save the settings file. To a certain extent it is a case of practice makes perfect, I doubt you will ever remember every setting as there are just too many but you will get used to where to look for particular items.
Keep going it will get easier, not simple but easier.
John