For the last few years I've believed Excel is the most important piece of software written, no hyperbole. The reason is that it's so damned accessible. Software is eating the world, and letting people who don't write "true" code still kinda write code opens up software's productivity and automation benefits for a bunch of use cases and an insane amount of people.

For programmers, the analogy is python. It's almost never the best tool for any specific thing, but it's a really solid tool for a ton of things. It's easy enough to learn and has enough depth to keep learning. It's easy to prototype a quick answer, and can not-to-painfully grow to a large complex system. I think that's why you get people from all backgrounds using python. It enables people who don't know much about software to start writing software.

Excel's the same way, but with an even lower barrier (and probably lower ceiling). It enables people who don't know anything about software to get many of software's benefits. That's huge.

Just like python can great for a biologist whose focus is biology not software, Excel is great for the accountant whose focus is accounting, not software. It makes them a programmer, or at least close enough for many many purposes.