Besides just minimizing jobs in big open areas, and that includes putting stuff in stockpiles, you can also help design your accesses to open areas in a way that minimizes how dwarves path through them.
What does "you can also help design your accesses to open areas in a way that minimizes how dwarves path through them." mean in practice?
I use quantum stockpiles (for most industries).
I do lock entrances to unused mines.
What else?
Large open areas should be at the ends of the fortress for example and adjacent area should connect. The basics of it is at any given point a dwarf is first going to try to take a straight line path to their destination. If that path hits a wall then basically the pathing will spill out from that line at the sides trying to find an opening or way closer to the target.
So take this random fort image I found:
If a dwarf is trying to go from critters -> mess hall the pathing is going to try and move north and east as much as possible. That means the pathing has to fill out and check a fair bit of the storage room, most of the barracks, that room to the left of the mess hall, and the hallway towards the messhall. There's some savings depending on which directions are expanded first, but in general that's the issue. When the pathfinding can't take a straight line to get most or all of the way to a target the pathfinding takes more time to sort of feel out all of the ways it has to check.
I think this can be especially relevant in 3d space. The pathing has no idea where stairs are and the way pathfinding works is it checks for paths by looking at the square that's estimated to have the lowest pathing cost/distance to the target (this cost is always estimated below the actual cost). Typically this is going to be done using a straight line calculation ignoring all walls/collisions. So if you're dealing with a big room below another big room and a central staircase on the opposite end of the fortress the pathfinding is going to choke a bit. it's not going to know how to efficiently find the stairs so it's going to check a lot of the current level to figure out a path to the nearest stairs. That sort of thing is a drain on FPS.
Now open areas themselves aren't necessarily the problem in every case. A square single room fortress should actually pathfind pretty well. I think caverns and the like cause a lot of issues because they're open, but not completely, so the pathfinding still has to figure out ways around obstacles and that tends to cause a lot of space to be checked for pathing.
Generally I think where fortress' struggle with this is with stockpiles. Since you need so many and they are large open areas they tend to be areas of the fortress where dwarves will try to path through them when there's no route. That's why quantum stockpiles help so much.