Do you have experience as a farmer? If you don’t, why should I believe that farmers who continue to till their fields know less about this issue than you do?
Tilling and using crazy amounts of mineral fertilizer definitely improves yields. But it will, in the long term, also kill agriculture to a large extent if we're not careful. We're not talking about highly speculative outcomes here: The data is pretty clear and everyone with even a large pot and some soil can run the same experiment at home and come to the same conclusions.
Farmers need to survive, they need to earn money, they will obviously optimize for short-term yield. We shouldn't judge them for this, but we _should_ find ways to solve the issue, ideally together with farmers.
The no-till experiments started when the destructive effects of deep deep plowing started to appear (e.g dust bowl). It's a clear sign that society realizes that the local optimum isn't sustainable.
No-till is actually quite technical if done right, often requires some level of herbicides or way to cover the soil.
The argument "why didn't we do it before" is moot, before the 19th century midwives didn't wash hands either, why are they even do it now? Right?