What is the clearance? Pricier alternatives: Baskets, decorative boxes, even low cabinet drawers. 15" tall cabinets from a kitchen (or big box) store, and place on a small base (to be able to swing the door open if the cabinets are modern frameless style, and the floor is uneven). IKEA should have some great storage alternatives. Or a store like The Container Store. We had a bedskirt in our former life, and it easily got filthy.
This says it has an 18 inch drop
https://www.bedbathandbeyond.com/store/product/smoothweave-trade-18-inch-tailored-bed-skirt/132202?strategy=pdp_cav
Thanks! I can find 18” drop bed skirts. It’s the “riding around” issue that @BunsenBurner mentioned that is the challenge. The Velcro ON the slats is a good idea. 
Yes, I am not a fan of bedskirts in general, so I’d prefer not to have one. Some of those boxes are pretty, but I am not sure they would hold as much as my tall plastic tubs do. No matter how attractive the container, I’d really prefer that whatever is under the bed not be visible. I’m about ready to try to purge some more. If I can get rid of a bit more, then maybe what I have left could be under the center of the bed and wouldn’t be visible. I’ll have to find a better stash for our luggage. We have three pieces - one medium bag with a small bag that goes inside and then one other small bag. If I can remove those to a closet that would help a lot.
The IKEA MALM boxes are very innocuous - the dark colors would not be much noticeable under a bed. They’re a little deeper than most of the other underbed boxes. The fronts are almost 12" so you could pile stuff up at least that high. and it wouldn’t be seen.
https://www.ikea.com/us/en/p/malm-underbed-storage-box-for-high-bed-black-brown-20252718/
We have regular bedskirts on both of our queen beds, and tons of stuff stored underneath in various boxes and bags.
Why can’t you put the velcro on the metal frame?
DD has an ikea bed frame in her extra bedroom. No box spring just a mattress on the slats. She has a tailored bed skirt (not the ruffle kind) and it is just under the mattress. Doesn’t move around at all. Not sure where she got it, maybe BBB?
Major progress today!! I put our Christmas ornaments under our guest bed (which is very low, but they are in low boxes so they fit). It is also a king. I purged and organized our MBR closet which enabled me to get our larger suitcase in there and out from under the MBR bed. Now what is under the tall platform bed in our MBR is in the middle and not visible at all unless one bends way down to look for it. The bedskirt is gone, I will not be replacing it. I really like this tidier/streamlined look so much better. I like being able to see somewhat under the bed when walking into the room. Much easier to clean and access what is under the bed. Now I can shop for fun bedding that doesn’t include a dust ruffle/bed skirt! Yay!
Best tackling of the problem! Hope you are enjoying your new place.
It is so fabulous! Looking forward to when we can have some guests.
Be careful what you wish for… there is a line of CCers already patiently waiting for an invite! 
Congrats on your new digs!