[tnolet]

This is very true and rings close to home.

I was a solo dev / sole entrepreneur for ~2 years, then raised. My product could be considered core. This meant that at about 1,5 years in I was basically unable to take a holiday (picture me sitting on the hotel bed during a family outing answering tickets, fixing infra).

Having continuity, support etc. all are basics you need to have once serious customers join. Even more simple, you need code reviews! You need a second pair of brains / eyes to actually make things better. Edit: and don't forget on-call. Being on-call for 2 years straight is not good for almost everything in your personal life.