D&D leaves a lot up to the GM to fill in that Pathfinder doesn't, but it's mostly in the subsystems. Pathfinder has all of the subsystems, to the point where many fans don't accept that you can swap them out for other ideas that might work better for their table.

But 5e doesn't leave core systems up to the GM. Magic items and encounter balancing are there as intended. They just intended magic items to be lame and bullshit, and encounters to be balanced around core rules.

But everyone plays with variant rules, classes are not balanced, or even particularly well thought out, and bounded accuracy breaks down completely around 10th level, because it's a half baked mechanic that stinks of "well, what if we didn't even try any more?"

The issue isn't that WotC leaves everything up to the GMs, it's that GMs have had to take everything on because they produced a broken game and released it to an audience that wanted to love it anyway, because it seemed like a mea culpa after everyone shat all over 4e.