I feel like the epic gear drop rate could be a little higher, and the chances of getting a duplicate small. I had an epic drop for Kaine that I had already acquired, didn't seem to benefit me at all!

This type of game is specifically designed to be a slow grind. It is meant for people to steadily progress over very long periods of time. Some of the oldest players of the game likely still don't have epics on all of their crusaders. I think that's a good thing. Since it is an idle game ("an idol game", har dee har), it's purpose is to be able to play itself whether you're there or not, so after setting it up decently, most people will just let the game run in the background while doing other things. It isn't meant to be your sole focus. That's why it is okay that it takes so long to get anywhere - because you're not actually "at" the game the entire time.