I know that it can work, like I said it's not a matter of if it can be done but whether it's likely to be done. And I just don't think they're likely to add Robin and not go much lighter with it.
Again, not saying it can't work, and Titans proves it can, but it's still fair to dismiss it because naturally a niche streaming property has less oversight and more freedom than a film ever will.Titans has a tone fitting for the Snyder-verse and features a perfectly fine Robin, both the older Dick and then Jason. Dismissing it as a niche streaming property doesn't disprove that it works.
You say that like we've had a ton of dark Batman movies - sure they've all been dark this millennium but it's only been 4, 2 a decade. The 00's had Batman Begins and The Dark Knight. The 10's had The Dark Knight Rises and Batman v Superman (the JL movies are too much an ensemble to count). And the first three honestly aren't even that violent - intense maybe, but not that violent. Nolan's trilogy was no more violent than any MCU movie, it's just the tone was darker. Now Batman v Superman, yeah, the warehouse scene alone hoo-boy...awesome, but very violent that fight.Personally, while I'm very excited for The Batman, I am kind of tired of overly violent and dark Batman movies. It's boring and expected now and I think adding Robin would be a chance to do something different and more complex with the character. Maybe he could even go a whole movie without killing someone.
Again, I guess it's just because I'm thinking of it in terms of superhero films rather than just Batman films - when I'm getting soooo much lighter fare already, having just one reliably "dark" hero is the more refreshing change of pace for me. We're not really hurting for happy smiling heroes at the moment you've got to admit. Dark hero films are relatively few, and honestly most haven't been done well. In the past ten years we've had The Dark Knight Rises, Kick-Ass 2, Man of Steel, Batman v Superman, Deadpool, Deadpool 2, Logan, Venom, BOP, and the Snyder Cut. And only like 4/5 of those 10 were good - 5/6 out of 11 if we want to include Joker. Then we've got over 20 MCU films (I'm not going to try and do the math on which ones were done in the past ten years), a few non-MCU Spider-Mans, some Fox X-Men, the 2 Wonder Womans, Aquaman, Shazam, and arguably the Whedon Cut of JL on the lighter side. And honestly even that feels like a cheat because Deadpool 1 & 2 and BOP are really light in tone films just get lumped into dark cause R rated violence. And then you got the first Suicide Squad somewhere in the middle of the light/dark but definitely in the not a good movie camp.
The genre's kind of light hearted heavy right now, which isn't bad but I'd prefer a bit more balance. To me Batman kind of helps off set some of that mountain of bright cheery hero films a bit.