There's definitely a lot of interesting things to cover with Close Combat. On one hand, it's an insanely powerful and spammable Fighting-type attack, 120 BP with minimal drawback (the downside being the defense drops), but I think I'll look at this less from a competitive standpoint and more from an in-game/flavor standpoint.
The Fighting-type I feel gets a lot of extremely high power moves because it's basically supposed to be the strongest physical attacking type, with its type matchups in one, and high BP moves in another. We have two 120 BP moves here, Close Combat and Superpower, that lower two stats, though Close Combat is more spammable because it doesn't lower firepower. It also has other very high BP moves like Cross Chop, High Jump Kick, etc. because it is the type defined by immense physical power, superhuman levels above everything else.
As a primarily physical type, its moves from a flavor standpoint get to have more power because I think they feel physical attacks can be counteracted by the burn status, which if inflicted, will halve the user's Attack making their physical firepower weaker. Contrarily, special moves cannot be weakened in such a manner, which is why they ended up getting the nerf in Gen 6 with 95->90 and 120->110 and 140->130 in many cases.
As for Close Combat and Superpower, I feel this has been something they've fallen into pretty hard before Close Combat became a TM with Superpower as a common tutor move and now Close Combat being a TM in Gen 8+9, but I think both need more limited distribution but should share being widely distributed strong Fighting moves, and less overlap between them. Not necessarily purely for balance, but also for flavor imo.
Because both work as "strong Fighting move" that can be widely distributed imo, but I think they need to more clearly distinguish flavor between them with their distributions. From a pure flavor standpoint, they have a clear distinction in my eyes that I feel can work: when I think of Close Combat, I think of something like Infernape using it: a lightweight, slim, and agile fighter that is very fast and can charge in and rapidly fire blows relentlessly. Superpower, on the other hand, strikes me as something more suited for slow, bulky, heavy fighters like Emboar: concentrating immense power and then delivering a single, heavy blow filled with strength and weight. In my eyes, things like Conkeldurr, Chesnaught, and Bewear shouldn't learn Close Combat imo, while things like Lucario and Infernape probably shouldn't learn Superpower.
Things like Throh and Ogerpon learn Superpower naturally but not Close Combat, which fits their fighting styles, while things like Urshifu can learn Close Combat naturally because their combat styles work for that kind of move.
I think those two moves should split up distribution and whatnot in that regard. Both as a STAB move and as coverage moves for other mons.
