The problem is that regular entrepreneurs and business owners still must share the market with venture backed startups. You're always one pivot away from some hotshot startup or bigcorp going to war to take away your marketshare by forcing you to address that "the market can remain irrational longer than you can remain solvent" -- in order to compete with VC-backed startups, you need /more/ than just frugality. You need actually better execution -- execution which more effectively serves market demand than your competitors.
I used to be a lot more bullish about this before 2020's interest rate drop and subsequent declining bond yields, and the insane injection of capital into the markets. But now, I'm not so sure. Investors are reaching quite a bit further than I originally had expected in order to seek yield.
As many of the comments (correctly IMO) point out, VC-backed start-ups trade money to compress timelines: for example, hire in two weeks what a non-VC might be able to hire across two years. When you have VC funding and more of it is available, it is in your interest to leverage that money as efficiently as possible to make the case for growth and further investment. Frugality can further hurt you if you are in a VC-fueled industry race because you’ll be outspent and outbuilt by your VC-fueled competition, and it will be harder for you to raise $.
That said, if you’re a regular entrepreneur or business owner, the script is flipped. You are always working within the constraints of profitability and (assuming no major investments are made in you), access to capital is difficult and expensive - debt and credit financing can only grow as a function of revenue and needs to be paid back (whereas VCs give you ‘free’ money, free-as-in-equity). Given that, if you make a dumb financial decision it makes more of an impact on your business. While you still want to go in on big (validated) bets, in general it makes sense to err on the side of frugality and spend less than you bring in.