No, this isn’t a cast iron thing. Using stainless pans, you can get nonstick effects that, in my experience, far outperform Teflon anyway. The process is called “spot seasoning.” I have cooked crispy, cheesy rice noodles with eggs with zero sticking.
I love my cast iron pans, but stainless is my daily go-to. Added bonus: use 100% copper wool to clean your stainless pan. The copper-coated wool at most grocery stores is problematic; you might get a few uses out of the coated garbage and then it starts shedding metal bits.
For the majority of cooking? Yes, you don’t need a non-stick pan. A properly used steel (or even aluminum) pan will work. Cast Iron is obviously loved but Carbon Steel is actually what most people want and has almost all of the same properties. But properly oiling your pan (and I actually love cooking sprays for dishes where I am using a neutral oil. Glug of “real” oil, get it up to temp, and then give a quick spritz just to make sure EVERYTHING is coated) and cooking at a high enough heat that your proteins can properly react and not “stick” to the pan will get you almost the entire way.
That said? Eggs and fish. Eggs very much are in that “nobody ever complained about too much butter” category but there is a lot to be said about a quick egg without any additional fats. And if you are cooking eggs these days, you can afford a 20 dollar specialty pan… And fish in particular is the kind of food where it is very easy to overcook it while waiting for all the appropriate reactions to occur so you can cleanly flip it.
If I were to downsize my kitchen (which I hopefully will be doing in a few months…)? That shit goes in the appropriate bin. But if you have the space? A 20-ish dollar restaurant supply store non-stick pan is AMAZING. And cheap enough that you can afford to get rid of it the moment you see any scratching.