In my opinion the high transaction costs does not make Bitcoin useless. It is still a great store of value and using it that way doesn't require frequent transferring. It is also the number one crypto currency for trading pairs on exchanges.
yes although it can effect it but not so. the transaction fee is in fact effecting the small trading, it will only effect the shopping for small items, for exxaple i am gong to recharge my mobile i have to pay government tax on it. and i also have to pay transaction fee which which is more than the recharging amount that i normally do for my mobile.
we can hope that this issue will be solve on preyority bases, because it is now creasing problems. people are now facing hard to do small transaction, although high transaction is not creating problem, but for small transactions the problems should solve.