One word: Monetization. If I can get you to use my hardware to do computations you were perfectly capable of doing on your own hardware given the same code, yo

One word: Monetization. If I can get you to use my hardware to do computations you were perfectly capable of doing on your own hardware given the same code, you're more liable to be comfortable paying me rent. Throw in that web apps have a lower barrier to entry in terms of grokking libraries written in a systems programming language, and you have the "Software Engineering world being dominated by Web Dev". Sad, isn't it?