How are individuals and society benefited by the difference types of professions?

Farming:

let's say all Farmers stop working as off today than for few months we will live on reserve then when no farmers step up, we will stop using quora and Start digging on our backyard and with so many trial and errors we will learn farming and world will change and May change forever.The point is farming can't be stopped we should consider it as a resource as important as anything for survival pf our race rather than a profession.So we are not including farming is the most important profession.

Doctor:

if doctor stop working then it's all about survival of the fittest if you have good genes, good you have chance to survive. The number of deaths will increase exponentially but I can't tell whether rich or poor nation's already have unavailability of doctors but Rich nation's don't.(btw i said doctors) i didn't include nurse or any other medical professionals because a becoming a 'good' doctor can take years or decades of training.

*I HOPE IT WILL HELP FULL*