Depends on if you have the proper breeding materials beforehand, which is to say in gen 6.
You won't be THAT far behind since you can SOS chain grind for Dittos with good IVs, but you will definitely wish you could start immediately, since the Destiny Knot is locked behind a 48 BP wall... which you earn by battling in the Battle Tree and Battle Royale. Which largely requires competitive pokemon.
...it helps to just Wonder Trade for a while.
Or catch a bunch of Pick Up Pokemon and fish for Destiny Knot.
Today I realised you need to enable communication with Guests, VIP's and Friends to collect friend coin bonus for trading. I just want to level up in piece without random people asking for link trades every five seconds.