What you say is true and a popular idea in the FIRE community.
There is a limit to it though because you can only cut expenses to 0%. So if you managed to become a completely self-sufficient person with no expenses at all, you'd be exchanging all that money being spent for time put into production.
On the other hand, increasing revenue has no practical limits. You increased your net work by 164k over those years. Maybe you could have brought in a much higher amount by starting/expanding your own business and increased your net worth faster.
Of course, cutting costs is a guaranteed return while increasing revenue has a lot of risk associated with it. Ideally you want to do both - doing more and more with less and less. That's the purpose of technology after all.
Ah, yes. But remember that a permanent drop in your expenses not only results in you having more to invest every month it also decreases the amount you need every month for the rest of your life.
This means that you don't need to earn as much and can retire earlier, which gives you back more time.