I've assisted my grandparents with the same UIs many times, it's just harder to learn things the older you are.

For example, there was a service my gradmother used pretty frequently, which required a password change once every 6 months. She memorized the regular login flow, but she always called us for help when the flow broke and asked her to invent a new password, provide the old password, and confirm with an SMS code.

None of it is inherintly complex or difficult, but when you're at that age, and not super tech-savvy to begin with, computers are super confusing.