Yes, you don't need to be rich to invest. You can even invest with just a few dollars. But believe me, there's a big difference between investing a few dollars and hundreds or thousands of dollars. I'm not saying investing a few dollars is bad. But the reality is, investing should only be done by people whose income is sufficient for their daily needs. We can't force someone who barely even makes enough to live on to invest. Furthermore, we must have an emergency fund before trying to invest. I have a friend who regularly invests around $30-$50 per month in Bitcoin and stocks. But he can't hold it long-term due to unexpected expenses like hospital bills and car repairs. He has to sell his Bitcoin or stocks when he needs money. This means he doesn't have an emergency fund or non-investment savings.
For investment, the primary thing is strategy or mindset while capital is secondary thing. There are cases in my community where people are investing small amount constantly in stocks (picking the right stock after rigorous search) for last 15 years and now their net worth is in millions. Moreover we now have another option of investment aka Bitcoin, here we don't need huge capital for investment rather small amount with consistency (DCA strategy) can serve the purpose. Their are other options available too, all we need is will to explore and invest in area of our interest.