I have been hearing noise recently that btrfs is risky and unstable but (knocks on wood) i've been running it for years now with zero issues. What am I missing?

btrfs is almost 20 years old now, so lots of people only used it back when it was newer and far buggier.

In my experience, btrfs is actually more reliable than other filesystems due to its checksumming abilities, but when it does fail, it's much harder to fix than with other filesystems (which will often try to continue on even when stuff is broken).

Failures in storage software are very rare. Which makes it very hard to test... (you need to run it a lot, for a very long time if you hope to find errors by chance).

Also, some failure modes are worse than others. The failures known as DI (data integrity) are the worst. Even though they aren't expected to happen to everyone at a certain frequency (because, again, mature storage software is comparatively very reliable), even a single DI error that happened to any user sets up a major alarm.

In the storage industry, the running joke is that after first DI in your product you lose funding, after the second DI you loose the product.

And it did happen to Btrfs quite a bit... I've seen it with my own eyes when a system didn't come back after power failure. (But I'm in the business of testing software storage products, so, it's less surprising that it happened to me).

So... it's perfectly plausible that you have never seen Btrfs fail, and it's been more error prone than eg. EXT4. The error rate is low enough so that if you don't actively try to cause the error you will never experience one. But, over a large group of diverse use patterns, the rate is still worse than expected.