Of course, there is a sweet spot between simplicity and choice (and that spot will differ from person to person) but I think a simple base with the option to layer complexity may work better. Where 5e dropped the ball was adding more complicated options later. They never really came up with those rules modules that expanded the game in new ways. Cie la vie.
That said, I will take a simpler game that is playable over a complex one every time. I loved Pathfinder when it came out, but three years into it I found the options were overwhelming. Most of my players had dozens of fiddily micro bonuses that would be forgotten, monsters and NPCs were a slog to design and play, and finding the official DC for every possible option was a massive headache (well, the rope is 2" thick, but it's raining and dark out, so that's DC 15 +2 +4, but you have cunning balance so that's a +1 to all balance checks...)
Personally, 5e hits that spot for me: crunchier than your typical ORS retroclone, easier than 3.x based d20 games. Not perfect, but fine. I've not looked into level-up (is there a free sample somewhere?) But to me, it sounds a lot like adding the fiddily Pathfinder stuff back into 5e. If you like it, follow your bliss. But i think 5e is more or less about where I want things and 1D seems to be fixings the issues without adding a bunch of new gears to get stuck.