Improvements such as instant speed and ridiculously low costs were introduced to counteract bitcoin’s shamelessly sluggish speed, massive costs and inexplicably huge energy consumption
The only reason why Litecoin transactions are faster is that its block interval is about 2.5 minutes. This might lead to the increase of orphaned blocks and faster Blockchain size growth. Bitcoin transactions are cheap (1 sat/vbyte) and they are going to become even cheaper thanks to the Lightning Network (instant payments) and the Bitcoin Core 0.18 update which will allow its users to pay a fee lower than 1 satoshi per byte.