It's neither consumers nor other devs. Although other devs suing because Cyberpunk had too much hype would be pretty ridiculous.
It's investors suing due to the hit to the stock price. Which is also a pretty pathetic reason to sue since they probably released the game in it's current state since investors were complaining about delays in the first place. They made their bed, now they should lie in it.
Erm, they're suing for being lied to. Investors were told the game was in a playable state back in Januari. The state the game was actually in was also held back from investors. You can lie to your fan base, yet lying to investors can become actionable. The fact that Sony pulled Cyberpunk from PSN is proof the game was not in a playable state.
CDPR shot themselves in the foot by telling people they could get refunds without discussing with Sony first. Sony got flooded with refund requests and doesn't want to make an exception for a functioning game, opening the flood gates for more and more refund requests. Hence Sony delisted the game, declaring it unfit for sale, thus being able to refund the game without having to change their 'no refund' policy. Investors see this as proof the game was not in a playable state, thus they were lied to by CDPR.