I think those eras had browsers that weren't capable of delivering on the promise.
If you only work with IE9+ (all the other browsers are quite good now) you will be working in a run time environment that is far superior to those available in the DHTML/Ajax era.
Another issue is that very few people know how to do large scale JS applications, where I work we do (130,000K+ lines of code, 900+ classes) but it has taken us several iterations to get to this stage.
I believe we are planning on making our tools open-source so hopefully people will start to see that large scale JS apps are very doable. www.caplin.com if you want to keep an eye on the open sourcing of our tooling.
We have a framework more than a library, we basically ship a framework that our clients use to create their own web trading applications. This framework covers many asset classes and many use cases.
It's not likely that any client would use all of our code and so we have build a tool framework that only pulls in the JS code that your application uses, this is done without a build and is immediately available (add a 'new namespace.sub.Class()' line and hit f5 and it will be in the js bundle you get.)
If you only work with IE9+ (all the other browsers are quite good now) you will be working in a run time environment that is far superior to those available in the DHTML/Ajax era.
Another issue is that very few people know how to do large scale JS applications, where I work we do (130,000K+ lines of code, 900+ classes) but it has taken us several iterations to get to this stage.
I believe we are planning on making our tools open-source so hopefully people will start to see that large scale JS apps are very doable. www.caplin.com if you want to keep an eye on the open sourcing of our tooling.