My father-in-law has been slowly retiring from his contractor business for the last several years. He's down to working 40 hour weeks these days. It's really hard for him to step back further because he's still a critical step in so much of the process. He's the only person at his company who can do certain parts of each job.
Prospects want to talk to him, specifically, because his name is on the business and previous customers refer to him by name. He can bring other people into the sales cycle but can't completely delegate it.
He's got to sign off on the quote for the work (rehabbing an old kitchen, for example). The business depends on these quotes being profitable, so he needs to be extremely confident in the quote, and the work crosses several domains within the crew. Recently he's been training a back office employee, who's seen years of work and how much it costs, on how to do this well.
And he's ultimately the one who has to inspect the finished work and ensure it's up to the company standards. Typical manager responsibility there. If someone on his crew does a crappy job, he's the one getting a phone call and has to rearrange the schedule to address rework.
Anyone with interest and aptitude for these tasks is long term aiming to start their own contractirs.