Earlier quoted context omitted.
The safety of your mothers' e.g. online banking, privacy, computer data(pictures, home videos etc) is less important then the company you work for (and probably has insurance)? update: Apparently for many here, protecting your family is less important. Sort of happy you are not my son or daughter giving me computer advice.
The point is that if you do what you suggest, either maintaining your mothers’ devices becomes practically a full-time job where you are on call at all times (and you end up fully monitoring what she is doing even if you don’t want to know), or, from her perspective, the internet is “broken”. Probably both.
Stating it will be a full time job is such an overstatement, i'd almost call it a blatant lie. Your mom is on FB, YT, and maybe a handful of other sites daily (so no popups for those or decisions to take there). You could also monitor and log and then apply block/allow rules later for when you visit for coffee or dinner. (if you want to reply something here about unprotected in that period, think about all the new bad urls not on such url lists yet for apps like uBlock)
And i only get positive feedback how well it works and how much they learned about websites and other internet services, the information leaked to 3rd parties, cooperation between companies. Even scared some contacts i have from social media like FB, Instagram and alike. Makes them a lot more aware of what is going on instead of giving them a list of known crap urls, again, maintained by some samaritan in an attic. Nice effort, i just think its fair from sufficient nowadays on the internet. In the time it takes these people to update the list, 1000 new crap urls have been registered.
And doesn't take that much time, sure you have to put in some more time then, simply telling people to install uBlock (or similar) and tell them that they are safe and secure with this application. I prefer to educate properly instead of just throwing some half *ed solution their way and having them figure out it fails in the end anyway.
Another note, the internet is broken, broken in many ways. And _you_ know this else you would not suggest any protection, apps like uBlock.