Good reflex to be sceptical, but I assure you that it is indeed my job
(to be fully transparent, I have been doing this for less than 10 years, but what I mentioned above is generally considered best practices in my field).
Regarding your very good question, both are useful. Anonymous feedback allows for people to be more transparent with their comments and concerns. You are right though in that there is a risk that you get feedback shared in bad faith. In my experience, it tends to stand out though, so it can be easily identified. In person or direct feedback allows for a better exchange/dialogue and also builds trust between parties.
As for BG3's development, I honestly don't know why Larian chooses non-engagement. I've seen other studios take the opposite approach regarding game development (Obsidian and Owlcat come to mind), whether in early access or not, with success (at least, from my perspective). A little engagement goes a long way, but I may be biased
