Can you simulate walking in any direction via a moving floor for VR?

Yes. There are already two solutions. Slippery Shoes and Large Ball. In both cases the person needs to be tethered on one place.

Ultimate solution is of course "Mirrored Legs". Camera sees when the subject is moving its foot and moves a platform to meet it. If the software is good enuff, no tethering needed and the blindfolded subject can experience running on all kind terrains and landscapes and even kicking a ball.

Deluxe version has "Mirror Hands" too so you can crawl on a battlefield and do mountain climbing.

Do you feel like you're simulating walking a direction when you are walking on a treadmill? If yes then there is a reason why people have played around with developing this already. 360° moving floor treadmill directional controllers are a thing, I haven't personally used them, but they definitely sound like they could add to the immersion and cut down on people's disconnect between their inner ear and what they are experiencing with their vision.

I'm not sure for Virtual Reality, but Jamiroquai figured this out in the 90s for Virtual Insanity: https://youtu.be/4JkIs37a2JE