If you slow grow and keep it smallish, then it’s a “lifestyle business”. That number can change but maybe $5million or less ARR. Thats enough to pay yourself and a few staff with benefits.
But like palata said above, it is a startup if hasn’t found product-market fit.
Solid? Right up to the point some funded start-up starts giving away the same thing in the hope that they can fake it until they make it and take everybody else in the same space down with them.