For me Deno has a really nice security posture, the permissions model is just something I haven't seen in from other runtimes (JS or otherwise). There were other nice features (native typescript support, compilation to a standalone binary), but the permissions model was just unique.

https://docs.deno.com/runtime/fundamentals/security/

Like a decade ago I got into a huge fight with a Staff Eng at our company over Dart. I had just been put in charge of the company's architecture and one of the first things I did was migrate everything to TypeScript (which was relatively new at the time). He was so angry I didn't pick Dart. Good choice by me in retrospect (though picking Angular 2 over React not so much).

well Deno was the only player who could have prevented recent npm security disasters:

built-in permission system for filesystems and etc

just forbid writing to important folders like ~/.ssh

But it is Open Source, so if said companies like Deno enough, all they have to do is pay for its continued maintenance and development. This is one major thing that sets Open Source apart from proprietary software.

> Do they also do their front-end in Dart?

Hey, you jest, but Flutter has a lot of traction!

(I conceptually like Flutter, but I can't get over the Dart thing, so I'm not part of that traction.)

Slack? I think some of their plugins API was all Deno based for a while.

> Do they also do their front-end in Dart?

This is actually a good decision though.

> Companies went all-in in a barely established niche player with 1/100 the traction, instead of sticking with Node, and even better an LTS Node, and are now surprised?

Wait till you hear about this thing called Bun.

Though with a tiny core team and almost carte blanche AI credits, they are a lot leaner.