Every technique is in competition with rival techniques. This inhibits the development of new techniques, even if they have high potential in the long run. To succeed, they have to beat out existing techniques in the short run.
For example, there are potential advantages for superconducting electronics for computing, but CMOS keeps improving. It’s a moving target: it’s not enough to be good, or interesting, you have to be better. Soon, not in 50 years. This is particularly difficult considering the enormous amount of resources currently invested in improving semiconductor computing technology.
In the same way, one successful domestication tends to inhibit other domestications. Several crops were domesticated in the eastern United States, but with the advent of maize and beans, most were abandoned. Maybe if those Amerindians had continued to selectively breed sumpweed for a few thousand years, it would have been competitive: but nobody is that crazy. Pretty crazy, but not that crazy.
Teosinte was an unpromising weed: it’s hard to see why anyone bothered to try to domesticate it, and it took a long time to turn it into maize. If someone had brought wheat to Mexico six thousand years ago, likely the locals would have dropped maize like a hot potato. But maize ultimately had advantages: it’s a C4 plant, while wheat is C3: maize yields can be much higher.
Modern scientific plant breeders seldom or never start with a wild plant and try to domesticate it. Instead they modify already-domesticated plants. Many wild plants could be domesticated, but people aren’t willing to put in the huge effort required to get that plant to the point of being competitive with existing, highly optimized crops.
Maybe they should: but there’s a huge startup cost. Plant breeders at the University of Arizona made efforts to domesticate buffalo gourd as drought-tolerant source of oi, protein, and starch. But that was 35 years ago: the natural fate of such long-term projects is death by boredom, impatience, and retirement..
Why didn’t people domesticate foxes, back in the day? Is it because foxes are solitary hunters, don’t have the right pack structure and thus can’t be domesticated, blah blah blah? No: they’re easy to domesticate, at least they if you’re a crazy Russian. But we already had dogs: what was the point?