Some people argue that the requirements placed on public companies (like mandatory quarterly reporting) add operational overhead that might cause a company to postpone an IPO until they're larger or more established.

In practice, companies like Stripe, OpenAI, etc have stayed private because they've been able to access the cash they need at valuations they're happy with and because no one wants to open their books unless they have to. They aren't staying private because being a public company is hard.

Combining this with a SPAC a startup would be able to have a six month runway as a public company before having to disclose finances. I imagine that would be attractive to some firms.