I have kids in both these age groups and they are more alike than different. I think the younger set is slightly better with technology and much more diverse in their musical taste than the older ones were at the same age. I guess they don't have a generational difference if they are all siblings though.
You would think that's the case, but in my experience it's not.
Millenials were around during a major shift/evolution in general home computer use, so we're much closer to understanding the "flow" of tech, even if it's older. Gen-Z tries to think in smartphone or tablet mode.
Younger Gen-Z are the same as a blue collar boomer: when the company I work for hires a Gen-Z employee, I spend a ton of time with them the first few weeks "fixing" their "broken" machines. Most of the Millenials that are hired can do the general troubleshooting themselves.
I'm oldish GenX and maybe atypical but was a very early adopter of tech, on Usenet as soon as I could connect to anything, and was tech support for the older kids (but both got very tech savvy boyfriends) and of the younger set only the 19 year old has outpaced me. But I do think, if generalizing:
I can work computers because I had to fix them and like to mess with them. So everything now seems so easy in a way - I set up a network in my old house, wires everywhere, testing testing fixing, blah. Was dreading doing it when we moved - nope, mesh system, scan a code, boom done! Amazing!
Millennial kids don't expect everything to work but seem stumped when it doesn't. This may just be my kids because I fixed stuff for them.
The younger ones are used to everything working seamlessly and it does for them. That mesh network setup did not awe them, they expected it to be that easy!
Former gen-x here (I was gen-x when millennial used to mean people who graduate high school on/after the start of the millennia, but they moved x back to 1980 leaving me in a weird place). I think the main difference in younger people today is that their technological savvy is more in mobile devices since they are so powerful and so connected that they don't really need PCs for anything. I first noticed this living in Japan because they had very useful, high-tech hand-helds very early on. As such, I worked with many around my age who could barely even use something like Excel and had no computer troubleshooting experience. It seems to me like many of gen-z or possibly alpha don't have the PC side, but are very good with mobile.