There are some plants like mint that can spread like crazy if you don't maintain it. I had mint spread from my neighbors fence one spring and it just started blanketing my backyard. I had no choice but to use herbicides. Also with age I find it hard to bend down to pull weeds. I mostly resort to string trimmers, some root puller tools and once in the spring some roundup to get me a head start for the year. Longterm I need to add more mulch but I need to fix the yard drainage first since I can't raise the elevation much.

I can only assume you've never dealt with a quackgrass infestation... pulling that stuff out of an established lawn or garden by hand is the definition of a Sisyphean task.

They really not needed in commercial agriculture either. Farmers know their craft and would do well without it, and wouldn’t have the additional finance burden.

Also Roundup doesn’t particularly work that well anymore. Ask anyone who uses Roundup in a commercial setting about it.