In my experience, having been a homeowner in Alberta first, then Ontario second - it's similar to software development...
Most tradespeople prefer to work on new builds, large amounts of stable work, without the hastle of renovating existing structures and all of the hidden issues that are quickly exposed once the surface has been taken away. (So... technical debt...)
As a contract IT consultant - sure, sometimes I take small "side-hustle" contracts if I am not swamped by my primary gig - but, I couldn't pay all mortgage if I was reliant on just taking small/odd jobs. Same goes for tradespeople.
Most tradespeople prefer to work on new builds, large amounts of stable work, without the hastle of renovating existing structures and all of the hidden issues that are quickly exposed once the surface has been taken away. (So... technical debt...)
As a contract IT consultant - sure, sometimes I take small "side-hustle" contracts if I am not swamped by my primary gig - but, I couldn't pay all mortgage if I was reliant on just taking small/odd jobs. Same goes for tradespeople.