The modern design aesthetic is fine, if you are comfortable that almost no consistent visual hint will exist to say if an active region in an app is a "button" as you and I would understand it. Sometimes they are underlined. Sometimes they have 3D look. Mostly, they are just regions you have to know a priori react.
Interface adaptability to landscape/upright orientation cause severe issues for people falling back on "the button is <there>" expectations.
Fundamentals like cut/paste/clipboard do not present consistently between first class (Apple authored) apps and second class (independent) apps like messenger and facebook.
The list only grows. Its a shit show, for people of partial ability, declining functions, loss of independence and agency only increases their vulnerability and whilst I like working with them, I am now exposed to far far more of their financials and private communications than I like, because the bloody software makes it so hard for them to use it, privately: They just don't "get it" a lot of the time.
I am not exactly young (62) but I've been soaked in the GUI since before it existed (online since '79) -These people are in the 70s and 80s, many of them only came into the modern era in their late stage, and are struggling.