As far as I can tell, most restaking tokens are designed for ETH for now. Not surprising considering how many layer-2 projects they have right now. You can probably wait a bit and see if existing projects will branch out to other networks like what usually happens with defi projects these days. Even if you search restaking on Solana or BSC, most of the time it is still in the development phase as of now, such as Picasso iirc. Btw, I don't think it is as hype as other narratives such as RWA, not sure if that happens because I don't follow the right influencer or most of them are still trying to get some deals before they shill them.