Indeed. Let's look at non DLC too. Little Mac casually might be seen as spam dash and smash attacks while competitively, he requires a lot of skill to be competent with.
You can get your cookie cutter Sora moves, spam Min Min smash attack, roll the die for RNG, but there is more to be done with them.
Also, in what world are Banjo and Kazooie spam to win? Their only real move like that has a finite number of uses a stock. If you lose to grenade spam, that's more on you. Also, just outright skipping the Byleths doesn't help your case. Terry is a FGC so his inputs alone add a level of skill execution for better and worse, and Kazuya, as much as I loathe him, probably requires the most skill, or at least the most different skillset, to use effectively. Also, calling Plant too new when its the oldest DLC.
Generally speaking, if you lose to spam, that's on you, don't blame the fighter if you don't force them to adapt.