Land? Enormous amounts of land are used to raise animals or food for animals, many of which could be replaced with slightly improved Impossible Burgers. Artificial meat is already pretty much acceptable and its primary constraint is the cheapness of real meat. Land is unlikely to ever be a constraint given demographic trends. If there's ever any pressure on food prices due to lack of land, meat prices will go up and a bunch of farms will switch to crops to use as input to artificial meat processes so they can produce more of it. That's a very deep pool to draw from.
As for not having any scientific process to fall back on, that's far from true in most of the world, even the developed world. Sadly the EU has been blocking the use of GM crops for years, supposedly on 'safety' grounds but in reality as a form of trade barrier designed to protect local farmers from having to become more efficient (mostly French farmers). So the EU isn't even using genetic engineering to increase yields, a by now very mature technology! Large parts of Europe don't even use advanced technology because the CAP subsidy scheme pays them to not grow food!
When you look around the world there's plenty of low hanging techno-fruit almost everywhere, except maybe the USA where new tech is embraced and farming is quite efficient already. But even then, there's plenty of tech on the horizon should we want it. Genetic engineering is still at the start of what it can do - it's capable of so much more than just pesticide resistance.
