It's not just language abstractions or lack thereof, there was a really fundamental issue, that makes what you say true - at least if we're talking about line-n

It's not just language abstractions or lack thereof, there was a really fundamental issue, that makes what you say true - at least if we're talking about line-numbered BASICs. None of those early ones had a proper editor. It struck me sometime after leaving BASIC, that the whole line-numbering thing was really kind of a cheesy substitute for proper text editing. Given the limitations of the day, though, it was adequate. But relating to your point, once your program grew beyond a screen-full, you were stuck typing things like "LIST 300-399" several times a minute, just to look through your code. Today we just page-up/page-down w/o thinking, it doesn't break the flow just to navigate through a program, but in 1980, those line numbers were In Your Face! For programs that fit on one screen, though, this wasn't such an issue. With something like the PET, you could even cursor around on the screen and change things almost like using Notepad.