Every time you have to add employees or equipment. You add costs.
Every time you grow to the point where two guy's can't handle the work. So you add the third person.
Then you have to add another truck trailer and equipment. Spit off the two employees with their own truck trailer and equipment. You pair up with the new employee. You are now running two trucks.
Thing is to add a second employee when you are working solo when you only have 40 hrs of work a week you will cause a huge cash drain on your business.
Now if you wait till you have 60 hrs at the end of your last season and add a second employee at the start of your nest season you have more business to cover the cost of paying an employee. Could add 10 more hrs at the start of the season but did not because you were at your solo limit then you will have 70 hrs billable labor. So you should be ahead.
Same with moving to your second crew. You have to have enough business to cover the costs of running the second crew before you add a second crew. Eventually the second crew will do the volume to provide a good profit.
As a business grows the breaking points change. 10 truck operation probably can generate enough profit to start the 11th truck without there being any work to justify an 11th truck.
Thing that happens is many businesses grow too fast and let their costs get out of hand eventually sinking them in debt. This can happen even to large companies.