When it comes to transaction speed “as is” between BTC and LTC, it’s a no-contest. The latter is definitely more suitable. But there are other coins that are better when it comes to speed and fee. Especially Digibyte and Navcoin.
But we are in early days yet. I believe the big winner will be a platform/service that converts all of the major and significant coins into a “stable coin/token”, which is used as the currency for almost instant transactions worldwide (online and offline) at very small fees. There are many smart people working towards this. Including by NAV developers of their Valence Platform, as well as those related to NEO, QTUM, Cardano and of course, Ethereum. We will get there in due time.