Ugh, not this again.

Apple's hardware support is fine because they only have to support a few bits of hardware. Microsoft's hardware support is fine because everyone (aside from Apple) sells their laptops preinstalled with Windows, and so of course they design them with Windows in mind, and test to make sure things work.

Linux's hardware support is also fine, if you buy your hardware with the intent to run Linux on it and look for something that's supported well, or buy something the manufacturer has built with Linux support in mind. All the "Linux hardware support is bad" stuff comes from people who already have a random Windows laptop or Mac and decide they want to run Linux on it, despite the fact that if they just did a quick web search they'd find a list of problems with their hardware.

Saying Linux's hardware support isn't good enough is like saying macOS's hardware support is not good enough, because you tried to run macOS on a random HP laptop. Run an OS on hardware that it supports well and your experience will be fine.

> UI is also not the stumbling block to Linux adoption

I agree that it's not the stumbling block, but it's a big one. The GNOME developers seem to like to completely change everything often, and break a bunch of things in the process. I don't know much about KDE; last time I tried it was in the late 90s. Xfce (which I use) is ridiculously stable (it's hardly changed at all in the 15+ years I've used it, and I think that's a good thing), but it's built by a very small team, and so it's always a bit behind on polish and covering all tasks with GUI tools. But I love it[0], and it works well and stays out of my way.

The other major stumbling block is commercial software distribution. Go check out a commercial software package's website, and unless it's Electron- or Java-based, you'll see one download each for Windows and Mac, and 10 different downloads for various distros and versions of Linux (if you're lucky!). I would hate to be the person who manages releases for all that.

I don't particularly mind, though: most of the software I use is open source and in my distro's package manager, and the few commercial apps I have work fine (because I run Debian, and most commercial apps will have a Debian download, or at least an Ubuntu one that can be made to work without much trouble). But that's just me, and an average user wouldn't want to put up with this.

Honestly, I'm afraid that too much desktop popularity would destroy Linux (and turn it into the ad-laden garbage that is Windows or the increasingly-locked-down prison that is macOS). I'm fairly happy with its current popularity, where hardware support and software availability are good enough for my purposes, but without the platform becoming too commercialized.

[0] Full disclosure: I was an Xfce core developer for 5 years in the aughts, so I'm a bit biased.