Yeah, the hard bit was the IDEs weren't as nice. You didn't have the Internet to look up the syntax of some function when you needed it. No Stack Overflow. No ChatGPT. No-one else's code to look at to see how they solved it.
Even something as simple as "what is the algorithm to determine which isometric tile the user is clicking on in 2D/3D space" had to be solved from scratch :(
I hear you. I've ended having to implement many of my solutions from scratch because 2D isometric knowledge is so arcane now. No one talks about it or designs an engine like this. From what i've gathered, most people use a 3D engine with a fixed orthographic camera perspective.
Even something as simple as "what is the algorithm to determine which isometric tile the user is clicking on in 2D/3D space" had to be solved from scratch :(