Or if you do want a manicured plot, just cut them with a lawnmower?

The bane of my young life was having the job of cutting the grass around the house - we lived in the country at the time and had about 1/2 an acre of lawn as well as fruit trees, plants, vegetables, etc.

We never considered using weedkiller - I just can't see the need. Isn't it just as easy to pull the weed out of the ground as it is to spray round-up on it and wait for it to die, before presumably anyway pulling the remains of it?

Ignoring the health implications completely, I can see some "value" of using round-up in a commercial environment where your dealing with 100s of acres or more but fail to see what benefit it provides in a domestic setting when the number of weeds is small enough that it would just takes minutes to remove them physically and toss them into a compost heap.

Digging weeds and their roots up one by one by hand out of cracks in concrete/asphalt is much slower than spraying. Also much more physically challenging, which is a metric I didn't care about when young and able bodies but nowadays is very relevant to me. I'm not saying roundup is good, but there are plenty of reasons for it to be appealing. I haven't tried the boiling water method yet, it seems like it'd be easier than digging but harder than spraying, unless perhaps one has a mobile, outdoor source of boiling water.

I rarely use weed killer on poison ivy to avoid coming into physical contact. Lawnmowers work fine for flat yards, but for steps down a steep embankment you really need a weed eater and weed eater + poison ivy is a major hassle.