In RPGs I dislike scaling enemies because they signal changes in the world's power level which are entirely dependent on my character(s) instead of relating to wider world. It sends the message that there in fact isn't a world of which my character(s) are part. Hence it emphasizes gameplay (action, combat, difficulty) over roleplay.
Of course I can see the case for making enemies scale, but I'd recommend doing it in moderation. We don't want to see level 20 rabbits and wolves, or level 20 bandits fighting level 20 guards just because the player leveled up a lot. For some opponents a higher level makes sense though, and scaling does too. Because if player characters can gain experience, why shouldn't other villains, adventurers and heroes be able to do so too? But this is taken too far when entire organizations, communities, and nations are included in the scaling process.
I love to see such things explained as part of the setting. Which goes two ways. First you can explain or depict why certain opponents grow in power, and secondly you can give hints and information about certain powerful opponents. For example that werewolves require silver weapons to damage / kill. And that vampires require stakes and silver weapons. That sort of thing. So long as the players aren't overwhelmed when combat begins they can usually mange a tactical retreat.. assuming the story allows that. Which is something to keep in mind.
Dragon Age Inquisition does some of these things fairly well. It limits the scaling to a small amount (roughly 5 levels) per zone but no explanation is offered for why your enemies keep growing stronger. Near the end you face foot soldiers which are roughly 15 levels higher than their initial versions when the game began. Why? No answer is offered. Just for the sake of gameplay. Even your own troops appear to scale at that rate. So the game could have explained that better (soldiers becoming vetrans perhaps). Like most games Dragon Age Inquisition emphasizes action gameplay over the roleplaying aspect.
One way to avoid that is to spice up the encounters by giving the opponents tactical benefits. For example by way of ambushes and smart tactical setups. Such as by combining 'tanks' (warriors meant to take a beating) with traps and archers. That would properly signal that a lower quality force can still try to adapt and deal with more powerful player characters (consider giving the option to sneak up on them, so there are no traps laid yet). Perhaps while waiting for a boss or reinforcements. The more in depth you get, the more difficult and time consuming creating such encounters becomes though. But I think that with a bit of thought for the wider (organisational) context you can come a long way and really draw the player into your narrative. The KOTOR games come to mind as examples for tactical encounters, opening vents to gass enemies etc.. , although they too use the scaling system.
It would be really cool if we could develop a system that could recognize player tactics and adjust AI encounters to show a plausible response. Including the ability of player characters to wipe out the entire force, so that the enemy can't adapt, because no one escaped to tell about it. Unless the enemy somehow observed it, or examined the battlefield afterwards. Which could be tied into the roleplay narrative too. Laying an ambush for scouts who arrive to find out what happened, and so on. Way too much work for average gaming company though.
Hope it helps 