Aftermarket for the Bronco will take a while to develop just like it did for the JL (and probably even longer since there was no JK like previous generation to slightly change up parts from). But the extensive list of factory options and accessories will help hold people over until the aftermarket matures. Did you see this list of accessories available?One thing to consider is how long it will take for after market parts to come out for it. So, for those of us who like to tinker and change things up, you're gonna have to pay a premium when these other parts come out.
Leaked Options List: https://www.bronco6g.com/forum/threads/leaked-2021-ford-bronco-options-decoded-engines-transmissions-gear-ratios-trims-colors-tops-packages-more.1606/
It's actually much more extensive than Jeep offers as OE options/accessories.