The original Back to the Future ended on a cliffhanger, with Doc racing back in time to interrupt a kiss and harness Marty for another adventure.
It’s your kids, Marty! Something has got to be done about your kids!
Sure, Back to the Future II picked up this thread, with Fox starring again as both Marty and Marty Jr. in a story set in (gulp) 2015. But in our multiverse world full of time travel and parallel universes, there’s a cosmos full of reality-jumping adventures for future McFlys to partake in. Heck, if Top Gun: Maverick can make a billion at the box office, why not roll the dice with another 80's reboot? And while neither Fox nor Lloyd might have it in them to star, surely they could cameo and hand off the baton to a new generation of comic time travelers?