Common complaints with Batman these days is the family has become bloated, some characters are stuck in a rut or rendered redundant, and Batman himself is torn between being the relatively grounded vigilante of Gotham vs. the over-the-top superhero of the Justice League who fights gods and robots.
Fans have their preferences, and no one character or take is necessarily superior to the other. I'd argue the heart of the issue is DC tries to do all things at once, when some things just have to give.
And I know it's easy to say "So-and-so should be killed off or retire" or "This character must be the hero forever and never change" but good luck finding a consensus on that front.
An advantage of the Pre-Crisis Earths was it could allow different takes to operate at the same time without stepping over each other. You could have an Earth where the heroes are relatively new or ageless, while also have an Earth where they can age and retire and pass on their respective mantles.
So, if you had to split Batman's world between two (or more) Earths, how would you break it down? Who would go where and how would they be distinct from each other?
Here's how I'd do it:
EARTH-1
Bruce Wayne / Batman
early-to-mid thirties; allies with Commissioner Gordon, but still considered an outlaw by the police & public; rarely leaves Gotham; no affiliation with Justice League
Dick Grayson / Nightwing
the first Robin; early twenties; striking out on his own to be his own man
Jason Todd / Red Hood
the second Robin after Dick became Nightwing; wasn't killed, but something happened to him that made him turn away from Bruce; the black sheep, prodigal son of the family
Tim Drake / Robin
just became Robin; Bruce is reluctant to have him around after Jason, but Tim is eager to prove himself
Barbara Gordon / Batgirl
became Batgirl around same time Dick became Nightwing
Duke Thomas / Signal
I put him here because I don't want Earth-2 overcrowded, and a relatively new addition can spice up what's otherwise a "basics" approach to the Bat-family
Alfred is still alive; Catwoman is still riding the line between villain and anti-hero; Harley Quinn is still devoted to the Joker
EARTH-2
Bruce Wayne / Batman
early-to-mid fifties; still capable even if he's past his prime; accepted by police and public as great hero; routinely works with the Justice League to handle world-ending threats; maybe married to Selina
Dick Grayson / Nightwing (maybe Batman II)
late twenties, early thirties; first Robin, became Nightwing, on the verge of inheriting the Bat mantle if not already; worked with Titans; mainly deals with Gotham while Bruce works with League
Damian Wayne / Robin
after Jason Todd's death (and he stays dead here), Bruce swore there would be no more Robins; he discovers he had a child with Talia; Damian basically barges in and declares himself Robin against his wishes
Barbara Gordon / Oracle
was Batgirl until she was paralyzed; now operates as Oracle; co-founds the Birds of Prey with Black Canary; information broker for Bat-family and Justice League; mentor to new Batgirl
Cassandra Cain / Batgirl
second Batgirl after Babs; runaway daughter of David Cain; dedicated to Bruce and the Bat-family
Helena Bertinelli / Huntress
I put her here because 1) Earth-1 already has a black sheep with Jason, and 2) this allows her to work with Oracle and the Birds of Prey
Alfred has passed away; Catwoman is fully reformed and part of the Bat-family, if not married to Bruce; Harley also reformed into anti-hero
UNDECIDED: Stephanie Brown
On the one hand, if she's on Earth-1, she can be with Tim as Spoiler; on the other hand, on Earth-2, she can partner with Cass and become another Batgirl