Ya, let me start by saying I defintely agree with this sentiment! but.....
Bitcoin isn't sleeping! It might never be able to scale on the same level as steem or other Alts, but i'm almost pretty certain there are plenty big things being planned there too. I reckon the team isn't sleeping anymore than Dan Larimer and the block.one guys or Vitalik Buterin and his team are.
Take Lightning Network, for example, obviously we all know it's a second layer protocol that has been very well implemented on the btc blockchain. And with it comes the possibility of instant transactions between nodes and peers.
Obviously this is a sort of answer to the scalability problem. Now I've heard, though I can't remember from where, that it is naive to think of this as the overall solution to BTC's deficiency, I say it just to prove my point that the team over there are working too. And who knows?
I said I agree with you, though, first because obviously numbers dont lie; and that chart up there shows clearly that the Alts are coming strong; for sure. I think BTC dominance will defintely, defintely fall. These alts are too awesome to cower under BTC so much like this.
Our steem is going places; the plans have been revealed to us. SMTs are coming soon. Bitshares is rocking. EOS is full of head turning plans--maximum scalability which BTC with all its Lightning will never be able to achieve; so many awesome decentralized apps that will make ethereum look like a kid. And of course we know ethereum itself is no pushover, so ya, good year for the Alts, and even better times ahead.
I will warn again though, NEVER UNDERESTIMATE BTC!
I agree that BTC shouldn't be underestimated, just like I recognize that a brand name can have a significant long term impact, but I think it is ultimately be one of many, and in its own particular case will exist mainly because it was the first . . . and how much staying power that will have long term I wouldn't know.