Well there are two general ways of financing economic growth - debt-based and equity-based. Equity-based is the main way that the startup ecosystem works, for example, though debt is also a part of it.

With little or no debt, economic growth will no doubt be slower in the short/medium term. But an equity-only system with slower growth might be comparable in the long-run, due to continuous growth with no principle drawdowns and setbacks from periodic financial collapses.

I don’t know of any research attempting such comparisons, everyone assumes debt is inevitable and doesn’t bother thinking about this.

Equity based growth (eg startups) is much much smaller in $ amounts. There are like $140B in equity investment vs trillions in debt financing.

True, though you have to include the stock market too, that's equity. US Bond market cap is roughly $120 trillion, stock market cap is ~$45trillion. So the equity market is about half the debt market, if you exclude govt debt.

That said, if somehow you had a similar hypothetical economy but with little or no debt, the equity side might be larger.

Vast majority of stock market cap does not contribute to company capitalization. Primary equity offerings on the market are rare and use only a fraction of total equity. Most trades are secondary and don’t capitalize the company. The entire bond market value is a capital raise for the companies.