thinking about next YEAR is completely pointless. we will be getting like 2 more sets before rotation even happens again, and there is still a filler set to be released in February, not to mention that we don't even know all of the cards that will be released in the first black and white set! the most we can do(or at least, the most we SHOULD do) is think about possible deck ideas for when the 1st black and white set comes out, but even then, that's stretching it. like I said, there is still a filler set to be released.
also, some people don't know how to beat them, and that is just a fact. there are also bad players and good players, and that is also a fact. SP's are somewhat hard to play, and yeah, in SOME games "luxchomp specifically" can be pretty autopilot but that is mostly against below average players who dont know how to beat luxchomp (or dont know what luxchomp is), and dont realize that their main attacker, who they are failing to get set up is indeed open to an attack. BTW there is more than just luxchomp you know. dialgachomp, sablock, blaziken/sablock, straight blazechomp, HoPe, and then the random addition of SP engines and pokemon into stage 1/2 decks.
you have to know how it should play out and what you need to do in order to achieve that outcome, but even then it wont happen the right way every game. You have to know how to build a good list, and when its right to do different things in a game.
like dialgachomp for instance. you have to know when to tank, and when to go for the KO with remove lost. its not always easy.
especially when its SP vs. SP. its a counters game the whole way through. you have to know how you can either get a KO or a revenge KO, while also preventing your opponent from being able to score a KO on their next turn.