Do they really have a choice? Deno is not particularly faster than Node and Bun outperforms both, so Deno has to find a place somewhere between the two. Ecosystem ultimately matters more than speed, thus Deno is making the smart move, as much as I would like to move entirely beyond Node.
*Bun outperforms both on some metrics, which Deno has committed to matching/beating, neither of which may be the actual deciding factor in success since performance isn't everything