I tried them back in early 2020 as I thought I'd experiment whilst there were no races so I wouldn't really lose any ground . My take:
I can't help thinking that surely these only make sense if you train in them and race in a more forgiving shoe. Otherwise, yes, you are eccentrically challenging the lower limb more in training and supposedly adapting to make certain structures stronger, but then you are asking more of them during races. The net gain is minimal (no pun intended). I had no issue with the 'break-in' period over a few weeks, btw.
It makes much more sense for walking, as the benefits are applied directly to all functional tasks. I am much more sympathetic to those who use Vivo/Vibram/similar for S&C training and general walking if zero-drop is the USP they're after.
I liked the Altra toe box, that makes perfect sense, even if they are too wide through the midfoot, which for me was uncomfortable (I have narrow foot and find Nike a good fit).
What put me off using them ever again (and why I don't, as I thought I might, train in them and race in a more forgiving shoe) was the build quality. Eyelets breaking, and stitching layers coming apart on the tongue and upper gets really old especially when the shoe itself isn't that enjoyable or groundbreaking (it was Paradigm). Maybe this has been solved but I've heard of others with similar concerns.
In short, I'm just not interested anymore, with the caveat that certain manufacturers do need to be mindful of their toeboxes.