Tipping with $2 bills was a "cool" thing oldsters would do, because the bills are a novelty but not actually that hard to get. They'd also give them for birthday money and such (I have a bunch in an envelope somewhere for that reason).

You're right that at this point you'd need to be giving out a lot of them each time for it to count for much. Dollars are worth so little that we're beyond "let's get rid of pennies" and approaching "WTF is the point of coins smaller than the quarter?"

[EDIT] That first bit comes off as harsher than I meant. I just mean that this was a more common thing years back, lots of folks of a certain generation (or couple of generations) did it, and at this point I can definitely see how giving out $2 bills, which was once novel (though when the eighth older person did it in a year, not so novel...) and also a decent amount of money, is getting into "yeah, thanks for the two whole quarters, grandpa, I'll be sure to buy a candy bar with them when I get several more" territory, thanks to inflation.

[EDIT EDIT] I'm struggling with internalizing new prices, too, incidentally. I've finally learned that when my kids get $10 it is not worth getting them excited about going to get a toy with it. They'll need, bare minimum, double that amount, and even then there won't be a lot of options after tax. There's almost nothing they can get with $10 but candy or shitty collectible (ahem, kiddy gambling) card crap.