100% this - a good chunk of initial traction for YC companies is other YC companies - which is great in some ways to bootstrap initial growth/credibility, but the uncharitable view is that it's a Ponzi scheme in a way.
I think Ponzi is an overstatement, though I agree with the general sentiment.
There's in principle nothing wrong with clusters of companies that are inter-dependent on selling stuff to each other. Car parts manufacturers live and die by the big car companies - and to some degree vice versa - but we would hesitate to call that a Ponzi scheme.
The key is whether or not this clustered ecosystem is bringing in money from the outside. Somebody in the ecosystem has to be making money from the "outside" world. It's the sustainability of this outside connection that really matters.
For a lot of SaaS companies I think the rude wakeup is that the "outside" source of money was never an actual business but instead was just endless rounds of VC cash. Likewise (and IMO more offensively) with crypto the "outside" money source was hyped-up retail investors (and hyped-up VCs) and not any actual useful business.
I do agree though - the VC sphere has spent the last 10+ years building up an entire web of companies that inter-depend on each other but where the "outside money" was always highly dubious. This is distinctly unlike the older crop of BigTech companies where the outside money is (relatively) stable: actual advertising, actual hardware in people's hands...
100% and legitimately have nothing but respect for YC. Ponzi is definitely an overstatement which I used to make the point that in-network traction is potentially a risky signal of product-market-fit which was obfuscated when everyone was being rewarded with gobs of money for early 0->$1M traction.
