Talking about inflation which is very big if it is calculated annually, but are you going to maintain the same income in a matter of years? are you not investing and so on to sustain your life against inflation? if not then you have to do it, because if I have to talk about inflation by fiat, every year it will definitely decrease the exchange rate, so we compensate for it by investing or getting more income so that life can be maintained in the long run.
If you didn't earn much, you won't able to invest much.
Yeah you might make profit from investing for few years, but we don't know what happen in the future and your investment might not enough to cover your life.
Most people do invest, most people do find other gigs to earn extra money. But, most of them choose not a good investment e.g. not surpass inflation rate or they choose gigs that can't be leverage e.g. food delivery instead of singer, actor, programmer etc.