The only ongoing real world ish use case are the various stablecoins that run on it. I don't know how well they run on it, or what's in it for ETH's value.
If there is to be a bubble I'm really interested to see what alts do.
i'm pretty sure they're gonna do what they always do---bubble as well. in 2017 i watched 2014's deadest coins rise from the ashes. there was no fundamental reason for that except that people were desperate to put their money into something, especially if it hadn't pumped yet. because even the shittiest of shit was getting pumped.
i can't imagine that mentality is gonna change the next time bitcoin bubbles. it's always the same thing......."bitcoin is too expensive, i'm gonna buy the next bitcoin".
as long as the bitcoin market itself is propped mostly by speculative value, i think this will continue.