My biggest reason to use it less as digital cash is the obnoxious tax treatment. Sure I'll send zaps especially because my lightning funds aren't coming out of the Bitcoin I bought anyway (thanks Ember Fund), but the idea of tabulating every small purchase on my tax returns is insane. We need sane de-minimis rules on purchase sizing just like foreign currencies get to get rid of this nonsense. Speaking for American laws anyway.
We'll see if this administration brings in a better situation in that regard.
And beyond that, yes, I'm going to get rid of my dollars before my bitcoin as long as people are willing to take that trash as if it's actually money. Except for when I've got people who I'm looking to otherwise give a nice gesture to in addition to buy things from.