How is NVC way any different? "I feel sad because you did X" is just sugarcoated "You are the one who made me feel sad by doing X".

I find the "uncover your feelings" the most questionable point of the whole framework. Instantly reminds me of Stephen Fry's

    — I am rather offended by that
    – So fucking what?

Long ago I made an observation that anger and other feelings are more of our perception of someone's actions than the actions themselves. From that time on "90% of everything is attitude" became one of the my favourite sayings. Also, I am not sure if NVC sits well with the fundamental attribution error.

Words are just a way of conveying meaning, and it's always possible to interpret someone's words as implying blame. A motivated listener can take the most impartial, detached observation and hear it as a blistering indictment.

If someone is told the words "I feel a lot of anxiety about our financial stability" it's completely possible for them to understand the "true meaning" as "You're a useless slob who can't hold a proper job and I hate you"

But this doesn't mean that words don't matter. We don't control the meaning we convey, but we do influence it. Choice of words and phrasing is a very powerful tool for that. There are other tools as well, of course. But getting the words right is the low hanging fruit for most people.