I lead a project built on Deno; it was not my call, just to be clear. Deno turned out unfortunately to be a miss and we had seen the writing on the wall. FWIW, we're moving to a much bigger Rust core program with node for JS user extensibility. (In other words, I'm not willing to risk using the deno_core crates.)

The one silver lining here is that Deno had already increased their node/npm compatibility. Migrating off of the jsr ecosystem and back to npm is going to be less painful than one might imagine. I expect present LLMs to be sufficiently good at the task, for example.

Do these runtimes have some value today? Sort of. But the cost of reimplementing them goes down, down, down. I made two bespoke JS runtimes within a year. Next year it will be even easier.

Deno/Bun see the picture better than I do, and they decided it was the right time for an acquihire.