Is there anything meaningful/gratifying to do in this game that's not MSQ?

[MistakeNot]

I used to really enjoying the game. However since 4.3 I haven't played nearly as much.

I would cap every week, Do GS lotto, Play card games. and get about 1/2 the weekly challange log.

In 4.3 I may log on once to twice a week for 1-2 hours No interest in capping. Pago Seemed a failure to me, The 1st zone was fun but Pago I can't get into.
I have little interest in getting all my jobs to 70.
I haven't truched SAM or RDM..

The game did not really change with 4.3, so it sounds like you have simply burnt yourself out on the game. That easily happens when you play a lot for an extended period of time.
Take a break. The game will still be there when (if) you choose to come back.