>I think power users are not the main target of Ubuntu. Then who is? Normies buy iPads and casuals stay on Windows. Is this why Linux can't gain any market share?
This isn't true any more, and hasn't been for some years, you know.
It was true but times change.
Microsoft chose to kill off Windows 10, which it once promised would be the last desktop Windows ever. Its replacement is bigger, slower, stuffed with adverts and upselling attempts, and has an artificial demand for TPM 2.
That's driven thousands of people to check out Linux, and if you don't know anything about Linux, then Ubuntu is the number one best-known distro. Many techies dislike Snap (to the extent of spreading lies like "it's not FOSS"), but it makes version upgrades safer, which matters more to non-techies.
(I say thousands so the pedants don't shout at me, but I suspect the reality is at least hundreds of thousands, maybe millions.)
Linux Mint is friendlier, yes, and so is Zorin OS, but both are based on Ubuntu.
Valve has sold millions of Steam Decks, which demonstrate that it's now possible to run premier new Windows games on Linux with performance at least as good as on Windows. All Linux users know their hardware runs faster and cooler with Linux than Windows anyway.
Chromebooks (which are as cheap as laptops get) outsold Macs (which are expensive) by revenue in 2017 in the USA and within 3 years in the rest of the world. ChromeOS is a desktop Linux, based on Gentoo. It has hundreds of millions of users who have never heard the word "Linux".
Companies with cloud-based IT are deploying ChromeOS Flex as a response to ransomware attach. (E.g. Nordic Choice hotels.)
Many of us see Ubuntu's characteristic desktop in shops, bars, travel stations and things regularly now. I hear its startup sound on trains. I have totally non-techie friends running Ubuntu at home. I've given Mint to lots of mildly technophobic friends and they get on just fine.
It's not over, but the year of Linux on the Desktop came about a decade ago, and the penguin taleban were too busy in-fighting to notice.
IMHO, Ubuntu is trying to gain market share by targeting non-experts — making Linux simple enough for normies and casual users. Casual users are generally less likely to mess things up on Ubuntu than on Windows.