> Manual work is good for people, especially young people (in my opinion).
I complete agree! Manual work is great for the mind and spirit. That's why gyms and sports became so popular in the 80s and forward. But getting a job in manual labour, odds are much higher that you will be doing the back breaking stuff - or working for an asshole boss. That inverts the situation and the work becomes bad for the mind and spirit.
Manual work is best done for yourself, or being the boss, or for a good company with decent pay if you're extremely lucky to find it. I'd switch IT to manual work in a heartbeat if it came with competitive pay and some decency and respect in the workplace.