Plumbing is skilled labour and requires school/training - proper apprenticeships take four years, though there are fast-track options.
Any "manual labour"? Certainly not true. Unskilled manual labour is a race to the bottom in most places and usually done by immigrants who can afford to work for peanuts.
Any "manual labour"? Certainly not true. Unskilled manual labour is a race to the bottom in most places and usually done by immigrants who can afford to work for peanuts.