So we have the latest jQuery UI in core.
The cold and hard truth is that jQuery UI is big and takes more than 0.3s to initialize on mobile – beside any file loading. And needs to load a big chunk of CSS as well. I don't have to spell out how huge this is. This is in fact pretty much incompatible with the mobile and performance target of D8. jQuery UI will not have significant improvements on that front in the foreseeable future.
If our priorities are well defined, this is a no-brainer.
- 1) easy 2) fast: use jQuery UI everywhere.
- 1) fast 2) easy: don't use jQuery UI.
I believe the current priorities for mobile are : 1) fast 2) easy.
I'm setting major since we want that answered to get going with the other issues.