Do you think millennials who grew up with the early Internet and home computers will be as bad with future technology as boomers are with current technology?
My wife and I started talking about this after she had to help an old lady at the DMV figure out how to use her iPhone to scan a QR code. We're in our early 40s.
No. If anything technological illiteracy seems to be increasing again with the younger generations. They've grown up on locked down systems that don't encourage learning and exploration. It's not their fault. It's the tech companies and the schools who have made deals with the likes of Google.
That's why I'm a big advocate for Linux and open-source software, because it's computing with actual freedom. It's good for people to realize that computers are basically just abstractions layered upon abstractions, but at the core of it is the simplicity of a switch being on or off (assuming binary for now). It's not "magic" like some companies are fond of saying. It's not even particularly complex in itself. It's just a lot of simple parts working together. If you starts to understand those parts, then technology becomes demystified and you can often imagine how the underlying parts of any given system might work.
Second, I'm guessing you're talking about things like the "hamburger menu" and "share" icons:
Frankly, those things are no more cryptic than the icons we had back in the '90s, and in some ways make more sense than the excessively-skeuomorphic-and-outdated icons we used to use (e.g. pictures of file cabinets and floppy disks for loading and saving files).