I like grid, but I think too many people believe it's the cure-all for everything.
For me, grid is not an option. The eight web sites I currently maintain all have to support IE11, so no grid.
Plus, grid doesn't handle certain design elements as well as Flexbox, or even inline-block do. There are certain design guidelines specified by certain government agencies and the consultants I work with that are simply not possible in grid.
I use grid in a few of my personal projects and it's useful for those. But grid is just another tool, like Flexbox.
As for Bulma, I watched the video and it doesn't appear to be anything special to me. It doesn't seem to solve any problems that a dozen other CSS frameworks do.
Also, if you're going to put out a 2:43 pitch video, at least make your fake web site look interesting, not like the other 542,234,280 other identical-looking Bootstrap web sites out there.