Do we really need another Max-centric film? Sure, I'd like to see Max again, but its nostalgia and dedication to the franchise concept that leads me to that desire, more so than any reason or sensibility. What kind of story would Max have now? It was done with the first two films and that's where the Max story perfected itself and resides to this day. What more could the character do that wasn't done in those first films? Perhaps a Gibson old-man Max, but that would have to be a pretty fine and unique screenplay to work. I don't think it would be an easy thing to pull off.
I fear extending Max's folklore means something more like Thunderdome, too much of the same thing, with Max engaged in further derivative adventures saving tribal societies from of their post-apocalyptic misery. That's all he really did and it was his only story. We only needed one iteration of it to work. Max doesn't have much of a character-story arc after the first two films and retreading that story meant laming it down quite a bit as we saw in Thunderdome (btw, I always thought the first half of Thunderdome was great, while the last half was bad... sort of like Return of the Jedi). In Fury Road Max's function was exactly the same and it seemed to work well because he was drawn back just enough and given purpose and meaning with equivalence to Furiosa's deeper story. He did his folk hero work as a catalyst for helping/saving others, while letting a new character have a larger and more profound purpose. I thought it worked quite well, kept me invested in the various characters' stories and kept me engaged in Fury Road as a sustained cinematic experience.
The Mad Max world seems to have more potential for telling other stories, of other character and situations that inhabit that larger folklore, now that Max's adventures are largely established, formed and sealed up in the 80s era of films. The sacrifice of bringing it to 2015 and 2024 respectively meant letting go of the established main character and passing the torch to a new chapter of characters, of which Furiosa was the most firmly established for this decade. It's a tough sell and a bitter pill to swallow for us fans of the originals, but I do believe the Max franchise benefits from an expanded universe approach of stories today. That's probably the most we can hope for and the only approach if we want to see this world on the big screen at all. We should be grateful that Miller is still able to revisit this world and deliver it to the big screen, rather than handing it off to a studio that would likely serialize into a terrible show for television and streaming.