Most of my friends are over 50 and their devices are not shared. They are real newbies. They don't use their PC for gaming or banking: they use an Ipad for banking.TouchID is very convenient. Most of them have 3 devices: a PC, a tablet and a cell phone.
Their PC setup:
Admin user, UAC Max, Microsoft Defender with Configure Defender, Hibit Uninstaller used for junk files cleaning once a month, Windows Update, Chrome with Adguard, sync Google Photos, calendar, contacts, Gmail and Chrome on every device. Bitwarden used as a vault for their passwords or and a small notebook.
Every 4 months or so: I check their PC with Norton Power Eraser, Sumo, Autoruns and Process Explorer; make a backup of their most important files on external drives. Make sure that every password is safe and on Bitwarden or notebook.
Some have learned how to make a backup on a drive.....
Most people have 3 devices or more. Security is indispensable, but synchronization is also essential.