Generally true. The next step of optimization would be automating parts of your job so you can reduce 8 hours of work to like 6 hours of work. Now you have more time for yourself.
even if you assume this is possible, why would your boss pay you for the 8 hours when it clearly is possible to only pay 6? You end up back where you're started.
The issue here is that the income you generate from your job is not enough. I dont know what the solution is - but under a capitalist world-view, the only solution is to own more capital, get that capital to produce your income stream (dividends or capital gains or whatever), and thus, give yourself back time.
AKA, this is called retiring, and if you can do it early, you end up with a better life, able to spend your energies on activities you care about (such as making this game).