That's a good point. I can see a progression like: developer finds new feature X that solves problem Y, developer finds that feature X is only supported by 20% of customer browsers, developer adds polyfill in XXX kB, buggy javascript library with other performance-related side-effects.
Maybe the issue is just educating web developers about what's available, and the non-obvious side-effects using feature X.
Here's what I'd like to see: organize a site like caniuse not by feature, but by tiers of support in the entire population of installed browsers. Something like:
Supported by 99.99% of user-agents: image tags, ...
Supported by 95% of user-agents: XHR, ...
Maybe the issue is just educating web developers about what's available, and the non-obvious side-effects using feature X.
Here's what I'd like to see: organize a site like caniuse not by feature, but by tiers of support in the entire population of installed browsers. Something like:
Supported by 99.99% of user-agents: image tags, ... Supported by 95% of user-agents: XHR, ...
(I'm making those numbers up).