What are you on about? You scrape the pan and get most of the grease out with a paper towel. For the incidental big clean you just wash it by hand with water and soap, but then you do need to oil it some to avoid flash rust.

Non-stick is much more fragile than cast iron.

Also, how do you deal with food sticking to it? How can you make pancakes or crepes in it, for instance? It seems like it might work fine for some foods, but poorly for others.

This is a strange question given that pancakes aren’t a particularly sticky food. This is kind of like asking how you don’t spill water on your face without drinking through a straw, there’s some potential for challenges but it’s pretty easy to deal with if you have a basic familiarity.

Well seasoned cast iron is pretty non stick. The added benefit of a Teflon pan is fairly marginal.

I mean... you just do? Pancakes and crepes especially work VERY well in a cast iron pan. You'll know the crepe is done because it'll start sliding around in the pan when shaken.

There's a lot of words out there about how to perfectly season a cast iron pan, but in my experience the best way is to just treat it sort of badly. If you want to be slightly more purposeful about it you can occasionally overheat some oil in the pan. I tend to just bang it back on the hob after cooking and heat the remaining oil/fat in the pan to the smoke point before turning it off.

re: scraping: I think you're overestimating the sort of scraping I mean. I'm not talking about scrubbing with a lot of effort. I just mean you take a metal spatula and scrape some of the burnt stuff into the trash. Doesn't really take any force either.

Yeah it's not quite as effortlessly nonstick as a nonstick pan, but at least I'm not worrying about flaking poison off into my food, and having to be careful with metal utensils. You can treat a cast iron pan badly and it'll make it work better, not worse. The one fragility it has is rust, and even that is largely overstated.