Sure, but that would be a very different kind of investment than the risk capital / venture capital investing in a startup. A stable and profitable company can

Sure, but that would be a very different kind of investment than the risk capital / venture capital investing in a startup. A stable and profitable company can (and often will) raise capital by loans, bonds, IPO or normal stock sale to investors outside of startupland on quite different terms and conditions. And, crucially, a stable and a profitable company doesn't need investment even if it would benefit from it, it wouldn't fizzle out without investment or (obviously) it actually isn't stable or profitable.