Sure but i doubt there is more image data in the delivered nextcloud data compared to doom2, games famously need textures where a website usually needs mostly vector and css based graphics.

Actually Carmack did squeeze every possible ounce of performance out of DOOM, however that does not always mean he was optimizing for size. If you want to see a project optimized for size you might check out ".kkrieger" from ".theprodukkt" which accomplishes a 3d shooter in 97,280bytes.

You know how many characters 20MB of UTF-8 text is right? If we are talking about javascript it's probably mostly ascii so quite close to 20 million characters. If we take a wild estimate of 80 characters per line that would be 250000 lines of code.

I personally think 20MB is outrageous for any website, webapp or similar. Especially if you want to offer a product to a wide range of devices on a lot of different networks. Reloading a huge chunk of that on every page load feels like bad design.

Developers usually take for granted the modern convenience of a good network connection, imagine using this on a slow connection it would be horrid. Even in the western "first world" countries there are still quite some people connecting with outdated hardware or slow connections, we often forget them.

If you are making any sort of webapp you ideally have to think about every byte you send to your customer.