Bitcoin has turned into the bank you have to go to if you want to buy altcoins
I don't understand what you mean. Could you explain?
There's often no route from fiat --> altcoin, instead you have to go from fiat --> bitcoin --> altcoin
I get it. You can't directly buy altcoins but you can always trade for Bitcoin. So Bitcoin only matters in so much as it helps get the altcoins. Interesting.