In work life as in the rest of life there is a mid-career crisis thing where you plateau and realize this is likely the best you will ever do. Crazy things can happen or you may float until there's a downturn and/or layoff but likely at some point the same old same old may appear to be a friendly shore you would not mind landing back on to finish your career. A side hustle can be a good way to do something you feel passionate about.