I developed Ext-JS applications from 2011 till 2017, and during the ExtJS 4 time, it was great. I loved the quality of their documentation, and most importantly: the ability to comment on each class/method/property etc. This contained invaluable hints and insights. The community was really good.

Then they upgraded ExtJS (can't remember if it was to Ext5 or 4.x) and deleted all the comments as 'no longer relevant'.

Then they started to move certain classes (such as a SOAP client) to the 'premium' edition. Which was understandable, but annoying if you just wanted to experiment with the framework.

Then they removed the GPL edition from the download page, the only way to obtain the GPL edition was by begging on the forums. Eventually Sencha simply no longer responded on threads about the GPL version.

Last year I did a small project and attempted to use Ext6, I found it had become a monster, or even 2 monsters because they split ExtJS into the 'classic' and 'modern' editions, which were promised to be merged eventually, but I'm afraid that's never going to happen. ExtJS now requires a custom build system (SenchaCMD) to compile a project, debugging is becoming a nightmare. Bugs in the build system are rarely solved once reported.

The way I see it: extjs was a great product, but they started treating their community like sh*t, and after that it all went downhill.

Goodbye ExtJS.