I use (and like) both. Bun is a drop-in replacement for node. If you don't want to fuss with test config, tsconfig, esmodules, etc., I find that it just works. Deno has a nice standard lib, great CLI support, and I used to love deno deploy but its gotten very clunky these days.
But if you look at the node compliance tests, deno has better compliance now days…
Insanely better, at 76% Node compliance in Deno 2.8.
Bun 1.3.14 is at just 40.6% with same compliance test.
https://node-test-viewer.deno.dev/
I guess Bun had the better marketing then. I liked how every new feature came with a benchmark against the previous version and node. See this for example: https://xcancel.com/bunjavascript/status/2048228152397459590
I'd love to see a site comparing the 3 of them in a similar way.