A couple of tidbits of necessary prereuisite knowledge:
Men's appendages are more on the front part of the body (towards the mons pubis area) rather than being directly between the legs like a woman's. For the most part, this alone is enough to prevent any balls or weenies from being crushed.
Our ballsacks are almost never as "high and tight" as they would appear when we're having sex - having them out, in the cold air, really tightens the boys up. The norm most of the time is for them to be rather loose and hangy (I've heard from many older men that this effect intensifies with age). This means they (the balls) have more skin to move around in, which is great if your goal is to not crush the lil fellas between your legs (since they'll usually move up onto your thighs rather than getting trapped in between).
This one isn't all that relevant to my points, but it's still good to know: Pain delivered to the balls feels like it shoots through the entire body; pain delivered directly to the peen itself stays fairly localized. Therefore, we prioritize ball protection since the peen generally sits on top of balls, mostly outta the way, anyway.
So that is sort of the basics of how/why we dont crush things down there. Most of the time, these features mean that manual intervention is not required, so you can generally just let things sit as they are. That's said, there are definitely still some moments that require an adjustment, but I would consider those to be relatively uncommon in the grand scheme of things.
What is more common, I would say, is BSTL (balls stuck to leg). This usually happens during physical activity as a result of the groin area becoming sweaty. If you're lucky, the "side step" method usually resolves the problem quickly and returns you to your regular life of (generally) not having to think about the placement of your dick and balls. Sometimes you have to reach into a pocket to try and make an adjustment. Sometimes you just straight up need to reach down there and get hands on to fix the problem. Generally, the setting dictates which method is appropriate.
With all that said, please take my comments with a grain of salt. I'm speaking from the perspective of an average sized dude and i can't recall ever directly discussing this with any other dudes so this could all be anecdotal. Also, I have no idea if the guys out there with magnum dongs and/or bull nuts have to deal with these types of issues more frequently.