And 25 years ago I job work managed a bathroom renovation company.
I had 7 different tradesmen for each job.
Timing was critical.
These subbies would go to another job if the job I had then booked for wasn't ready for them.
Demolition, then carpenters and plumbers, electrician, carpenters and plumbers again, tilers, painters.
More complications if a spa was being installed.
Life is not from a textbook.
You have to experience it before you make stupid comments.