Vehicles are always going to be trade offs. The 4 runner is probably a better family vehicle, the bronco is a better play vehicle. If you buy a new 4runner today at full MSRP, your someone that prioritizes reliability over all else. Ford is definitely still working out the kinks, and covid isn't helping. All the car brands reliability is taking a hit the last two model years. Reliability scores are lower across the board for 2021 and 2022.
I feel like the Bronco is for people that have always wanted a Jeep but can't bring themselves to give up that much daily driver quality for a serious off-road vehicle. Both jeep and ford have realized that you can offer massive off-road capability with tech and creature comforts and people will pay for it.
The bronco has significantly more off-road capability, more power, more creature comforts, more tech, more available safety features, better crash ratings, much better cameras, there's the topless option, easier to modify to bigger tires etc. However they have their own issues, they can be noisy, they don't feel like they are that well put together, the materials etc. feel cheap in a lot of areas, the back seat especially is not as nice. The bronco drives quite nice compared to a jeep but it won't drive like a KDSS 4runner if you toss it into a corner doing 60. The rear seats don't fold anywhere near flat so putting anything long and heavy into one is really annoying.
The 4runners I've been feel like they are more solid, quieter, perhaps slightly more comfy seats, reliability of course, and they have more cargo room and I'd say more useable cargo room as well. However, that's about where the good stops, the lack of power, tech, features, but premium price tag. Getting into a new 4runner almost feels like getting a 10 year old well taken care of used SUV with the tech and features or lack of.
The only problem with a Bronco is you can still find 4runners for MSRP on lots, but you find a loaded Bronco badlands with a Bigfoot package on it and it will be $20k over MSRP if you're lucky. Order one and you might not see it till 2025, and if supply doesn't improve when your order comes in the dealer still pay screw you with huge markups, and Ford is letting them get away with it.
Honestly the better comparison for the 4-runner is the Grand Cherokee Trailhawk (RIP for 23' now that you can only get it as a hybrid), more power and off-road capability than the 4-runner, better on-road ride, better off road ride, way more comfortable, better fuel efficiency, more tech and comfort. Only downside is reliability (it's a jeep!) and slightly less cargo room and loaded it's about $5k more than a TRD Pro.