Shouldn't all crypto be backed by bitcoin ?
Backed by bitcoin would ask the question what is bitcoin backed by? The answer is trust and faith by its users. Similarly every other altcoin is backed by trust by its users. There is not need for them to be backed by bitcoin - then bitcoin would essentially control the market which everyone may not like. Although most altcoins dont even get any development backing from its developers some may be there which are genuinely being developed and those would like to have their own ground.
How could a "Bitcoin Standard" emerge? For example, if you could pay for food service etc everywhere with bitcoin, would that be enough to essentially drive bitcoin as a backing standard ?
Being able to pay for services with bitcoin essentially means being able to pay with some sort of crypto, choice of which crypto to be used depends on the user. Each altcoin carries its won advantages in blockchains and fees. That decision rests on the user and hence nothing like bitcoin as a standard has developed yet and IMO not required either.