Fair enough there is a reason but you’re still trading ease of development for the dev with something on the side of the end user, who might not consider it a good tradeoff. I haven’t filled my hard drive with games and movies, I’ve filled it with programs that bundle a bunch of libraries for things I may not use. A user won’t say that the program makes up for functionality by being small but they may not install it at all if it’s too big (which I’ve definitely done).
You’re right it’s about priorities but I don’t think ignoring size and loading times is a tradeoff most people would accept.