I stopped cooking with nonstick pans over 15 years ago, and the only thing I've found that can consistently be a bit tricky is eggs, but really only if the pan isn't hot enough yet when you add the butter or oil, you don't use enough butter/oil, you try to scramble the eggs in the pan, or you try to lift the eggs too soon. So arguably it takes a little more attention to detail to cook eggs on stainless steel, but in general I really don't think there is anything that requires nonstick. But even for the limited list of items that are easier to prepare on nonstick, it's usually just a matter of learning how to adjust your technique to match the cookware.

I made the switch to stainless steel and cast iron pretty much on a whim after I first read about Robert Bilott's lawsuits against DuPont, at which point I discovered it made almost no difference to my quality of life at all to avoid nonstick. To such an extent that I have never been even slightly tempted to switch back, despite honestly not feeling a particularly strong motivation to avoid nonstick in the first place. I've just always figured cooking with steel is an entirely painless way to reduce my potential exposure to dangerous chemicals, so even if it ends up being pointless, I haven't lost anything of value anyway.