Litecoin blockchain activated Segwit on May 10 (two month ago) so it's not that. I see another reason here - Bitcoin struggles with transaction times, since the block size is only 1 Mb and not all the transactions can be fit into the block. This is the reason why transaction fee sometimes reaches as high as 10%. For the next 3 months (until Bitcoin activates SegWit2x) - Litecoin will be the fastest and the cheapest cryptocurrency to transfer - as it was the first one to implement Segwit, tested it and approved its benefits and lightning speed. After those 3 months the crown may be passed to Bitcoin, so the future of Litecoin will be uncertain.