difference being its an esoteric experiment. and that webapp is used regularly used by thousands.

naive of you to even compare both.

No ad hominem please. Both examples are cool apps built with the foundation layer not designed for the task.

- text markup language isn't a good choice for modern performant graphics editing apps.

- excel sheet isn't a good choice for 3d game engine.

The difference here lays only in the fact that for Doom 3D engine, authors had another choice.