Boomers are still struggling even with the modern, simplified UI. They would likely continue to struggle if we had Idiocracy style UI on things (big, bright colored buttons with pictures of what they do).
I know it's fun to rag our boomer parents and grandparents but it was boomers who designed the older, "complex" UI for usage by other boomers. Since boomers are now dropping out of the workforce (25% of it right now) it seems likely that the UI is being dumbed down for the much larger Gen-X/Millennial/Gen Z workforce.
Yeah, there's now a lot of people who have actually never used a desktop OS, and the only OS they've used being a phone or tablet. Those people are more having an influence on dumbing down the OS now. It's pretty crazy how compute illiterate newer generations have become due to shift in what is considered their primary OS. Some people don't even have laptop or desktops.
I see both kinds of Boomers. My dad, a boomer, is in the tech industry. He is a software engineer. My grandpa was also a software engineer. Everyone I know from his side of the family has been in tech.
And then there is every boomer I know that isn't my own family and they are practically luddites. I know the former can exist. But it seems rare.
Apparently a large portion of the population, regardless of generation, proudly announces their tech illiteracy. I'm IT, and these people don't even remember their personal email passwords.