Think you answered your own question. No real differences except more articles, $, and hype

And, let's be real here: engineering prestige.

Everyone wants to make an OS because that's super cool and technical and hard. I mean, that's just resume gold.

Using Linux is boring and easy. Yawwwwn. But nobody makes an OS from scratch, only crazy greybeard developers do that!

The problem is, you're not crazy greybeard developers working out of your basement for the advancement of humanity. No. Youre paid employees of a mega corporation. You have no principles, no vision. You're not Linus Trovalds.