But, IPOs became rather passé post-2010ish, for the truly depraved. Too much regulation, you see. SPACs are ever so much more exploitable. Though, IPOs continue to be successfully used to funnel money from the have-nots to the already-haves.** And so, here we are.
Yes, there have been people legitimately trying to use SPACs to finance efforts they truly believed in. My sense, having traded SPACs myself during the height of the frenzy was: much less than 50% had much of any real legitimacy. And, solidly more than 10% or even 20% were scammy as hell ... particularly at that time when the money taps were wide open and fraud was absolutely rife across many vehicles etc. (helped along by ... survey says: the very "internet" Silicon Valley made such a massive economic force...).
* On a much larger scale and with a much more "legitimate face" than some of the other "operators" better known in this area, generally
** See, for example: https://www.businessinsider.com/venture-capital-big-tech-ant... ... I'd provide more refs in general, but sadly, super pressed for time right now ... so, obviously, I would advise anyone to take what I've written without solid refs with the usual grain of salt. Plenty can be found with some searches (quite neutral searches ... i.e., no "leading the search engine" required).