Tyranitar and and hippo rreally strong pokemons, that u usually ll run on overused without running a sandstorm team based, just because they r good, and both(tyranitar better, cause he can easy match with pelipper) r good counters for rain teams. U can just run ferrothorn and kill every water sweeper so easily making them cry.
In Other hand, sandstorm teams sucks, there is only 1 sand rush playable poke, and isnt so hard to kill, just play some hippo/swampert/gliscor/etc and earthquake him(U can mach punch Conk him and OHKO, or any kind of priority move, there r a lot)
There is 0 problems with weather teams, some teams can suffer against rain if isnt ready for that, but thats more about team making than a true meta problem.
Excadrill is a good lategame wincondition if played properly, but there r a lot of mons who can do the same and they arent op for that reason.
And, at the end of the day, if u see a Pelipper, u ll see 90% of the time, Kingdra, Kabutops or ludicolo as partners, thats a good advantage on a non-teampreview meta bro, u can expect what is ur opponent doing and play around it.
Sorry for my english, isnt my mother lenguague.