There are jailbreaks for the PS4, and it seems more likely than not that there will also be jailbreaks for the PS5. The barriers for actors who want to exploit console compute power are not significant. But they are significant for regular consumers.
Building cluster out of machines you’re not sure you’ll be able to consistently jailbreak and therefore replace even in the near term is a huge barrier to building a PS4 cluster like the PS3 ones.