Indeed with the game now in our hands, I can see the 1st person perspective adds quite a lot of immersion to the whole experience (honestly I never had any doubt about this) but also makes this game stand out from the other crowd of well known open world shooter out in the market. So I am quite happy that they make this decision at the end, whatever time it took to reach it the end result justifies it. As you said most of the dev time was probably spent in tech and building expertise on 1st person gameplay prototypes with little time for iterating on the new systems.
I had doubts because I find 1st person games to be too responsive and fast paced to be enjoyed as a slow burning RPG like the Witcher is. That was mostly my concern. Plus the fact they had very poor gameplay showcases in my opinion (badly edited, couldn't focus on one aspect but kept jumping on different elements too quickly in their dive in videos - it was very confusing to watch. Now thinking about it I guess it also shows they were confused about how to market it).
I'm glad I eventually found the same pacing and mechanics as the Witcher in Cyberpunk though. And now with enough support and patience, they'll polish and improve the whole thing. Nothing in this world is either entirely perfect or bad. I just wish, despite all the flaws the game has, the bad buzz wouldn't prevent people from actually finding that there are some really genius moments in this game, especialy considering the supporting cast of characters.
And I also fear this bad buzz will end up back firing in a few years, with less AAA games actually taking risks to launch up new franchises with ambitious projects, but ending up milking the same game over and over with just a bit of new elements here and there. We could have had a Witcher 4 with Ciri and microtransations instead of Cyberpunk. I'd take Cyberpunk over a milked Witcher 4 everyday, no matter what's missing / bugged. Risk, even when ending in failure, should always be rewarded in art industries.