Land mines are not banned by any of the major powers (China, Russia, USA)

Countries that have banned landmines have allies who have not that will step in and place those mines if needed. If US EU relations (NATO) go south and war (not necessary with the US) looks likely Europe will get rid of those treaties fast.

We've banned the use of landmines globally?

Someone should tell Russia: https://en.wikipedia.org/wiki/Landmines_in_Ukraine

low effort agi-prop is low effort.

The US and the USSR never banned them. Most of the world did so they could claim moral clout, but make no mistake, if the shooting started they'd be buying them from one side or the other like crazy.

As former USSR countries, UKR and RUS never agreed to ban them. Same for cluster munitions. And we're seeing just how brutally effective both are.

Landmines are a great example of what would happen if you tried to get everyone to cooperate and go back to low-tech weapons—some countries would agree to do so, and others would laugh and invade them, guns blazing.