The 2021 result is interesting, but:

There is still some debate about whether warp bubbles really can do without negative energy. Recently, three theoreticians suggested that this claim was only true for observers moving next to the bubble. Plus, not everything that seems possible according to the theory of relativity actually exists—or is technologically feasible. For example, Einstein’s field equations can also be used to justify “white” holes (the antithesis of their black hole counterparts), Einstein-Rosen bridges (frequently called wormholes) and other exotic alterations in spacetime that no one has ever observed. That could be because laws of nature, as yet unknown, preclude such phenomena.

https://www.scientificamerican.com/article/star-treks-warp-drive-leads-to-new-physics/