The actual answer varies from day to day. The gold annual pass is the biggest effective discount you'd currently be able to get. Other than that, the occasional
DVC event (AK Safari, etc.) or access to the temporary epcot lounge... stuff like that. I'd never pay extra for any of that but that's the beauty of capitalism -- we can all decide for ourselves

The main problem, IMHO, is that nothing is guaranteed to remain. In fact, they could change the rules again in 2021 (for example) to say that a
majority of your points have to be direct or you don't qualify. Or, they could just remove all the discounts and perks altogether. That's likely to happen only if/when they stop selling new properties, which I don't see happening anytime soon considering how profitable this is for them.