This is patently and blatantly not true. I have installed Ubuntu to my mom and my wife's parents, and they are happily browsing internet ever after, without any malware or crapware. In the past few years I have spent ~0 hours on maintenance of these devices.
Previously, when they were using Windows, it was a never-ending nightmare.
You see, a well set up Ubuntu is perfect for people who need the computer to just work. They just can't break it!
My wife had an older laptop, which had a failing hdd and I used the opportunity to swap for a SSD and asked her to try Ubuntu.
Yeah, she had a lot of questions at first, but eventually she got used to it. She got a new laptop and had to go back to Windows due to her work, but whenever she is just browsing or videocalling anyone, she doesn't mind using the older laptop.
Also, guess which laptop always has issues with the printer?
In my experience any laptop on any system will have issues with the goddamn fucking printer :-)
I had an old dot-matrix printer connected to the parallel port for a very long time. Could "print" with just "cat file.txt >/dev/lpt0". It was great. Downside was I couldn't use it in the evening as it woke up the neighbours.
Getting volunteer coders to work in the customer-service style that is required to make a desktop for non-technical people just doesn't seem to work. And turning a volunteer community into a profit seeking one usually seems to hit these roadblocks.
We should just accept that success for Linux on the desktop looks like what we have now. Which seems fine to me. Everyone who wants it has it. Unending lust for growth is a trait of megacoroprations and cancers, not great company to keep IMO.