Welcome! You bring up an interesting point. A strong argument can be made that Superman is more effective as a character when he’s the only “super.” I agree with that sentiment to a certain degree. For me, Superman works best when he’s clearly the SUPERman. When he is, without a doubt, the most powerful hero on the planet.
However, that was arguably only ever the case in the Golden Age. Even Post-Crisis when Superman was the only “super” and, basically, the only Kryptonian, you still had characters like Captain Atom (the “Superman” of Charlton), Shazam (the "Superman of Fawcett), and Firestorm (a being arguably more powerful than Superman) running around the DC Universe making Kal seem less unique. So, if you think about it, Superman hasn’t really been the only “super” in a loooong, long time.
This day in age, it’s been about “the more, the merrier.” We have two Batmen, an army of Bat-children, a pair of Wonder Women and Girls each, and a whole lot of legacy characters. The same thing is happening at Marvel. There are so many characters to love and I wouldn’t want to lose them. So, I’m willing to allow that sentimentality to dilute Superman’s status. And, hey, it worked pretty well in the Silver Age…
The nice thing is, we seem to be getting the best of both worlds. People have been clamoring for Supergirl and Power girl content. Hopefully Action delivers. PKJ has done an excellent job so far so I think his portion of the Action run will deliver. And Williamson and Cambell on Superman? Lord! So there is a book for Jon, Clark and Lois, and the extended Super fam.
I assume the book will go up in price to accommodate the extra stories but hopefully it won’t be too pricey.
I am a big fan of legacy. It allows for more diverse characters and fresh takes on old stories. Even if I prefer the old guard characters sometimes like Clark, Barry, and Shayera, I also like Jamie, Khalid, Mary Marvel, Levi Swamp Thing.
Quite frankly, as much as I would love for everyone to get their own book in some fashion, there simply isn’t enough room at the table. I don’t think they should go away though. Quite the opposite. Put them in back ups and throw them on teams.
It worked in the Silver Age and it seems to be working for Batman and co. So in theory it should work just fine for the current climate of Superman books
For bronze age superman family, I remember lots of kandorians like Don-El, there was Nightwing and Flamebird from Kandor, there were many phantom zone villains like General Zod, Jax-Ur, Prof Vakox, Kru-El, Faora, Nam-Ek. I tend to view Mon-El and Dev-Em as part of the superman family. There’s also Lana Lang and Lori Lemaris. In rebirth, Lana Lang was superwoman.