They're a pretty isolated eco system, although it seems they're working to improve that. Right now they use their own ant-based build system, have their own ES6-incompatible class system and you're pretty far removed from HTML/CSS. So it's really hard to leverage "regular" JS frontend skills there.
Which might be fine if the system would work properly, as Ext would not directly compete with more "bare metal" component systems, but work as some kind of browser-based GUI DSL (which was what got a lot of people into it back in the days when DHTML was young).
Sadly, they seem more focused on introducing new features than fixing bugs or making all those elements work together (recent example: Conflict between new two-way binding and old statefulness of grid column sorting/order/filtering).
Mindshare isn't as good as with almost any other lib (some guy had the same problem you have with 6.2 with version 3.4, no solution ever posted), and due to it not being open source, there's not exactly a large community working on it, fixing things, adding new components etc.
And for all that, you have to pay a pretty stiff fee.
Which might be fine if the system would work properly, as Ext would not directly compete with more "bare metal" component systems, but work as some kind of browser-based GUI DSL (which was what got a lot of people into it back in the days when DHTML was young).
Sadly, they seem more focused on introducing new features than fixing bugs or making all those elements work together (recent example: Conflict between new two-way binding and old statefulness of grid column sorting/order/filtering).
Mindshare isn't as good as with almost any other lib (some guy had the same problem you have with 6.2 with version 3.4, no solution ever posted), and due to it not being open source, there's not exactly a large community working on it, fixing things, adding new components etc.
And for all that, you have to pay a pretty stiff fee.