From the wiki:
Standard Immersion Rig: pair of virtual reality goggles and a pair of haptic gloves, given to all new OASIS users.
The people on the street were using theirs. I believe you probably mean a "hamster-ball interior" or a "full-body immersion rig", which allows users to walk in-place to simulate real walking/running.
You don't necessarily need a full-body immersion rig.
While their OASIS movements would also cause movement in the real-world, keep in mind players can still see their real surroundings. We know this because Art3mis can see IOI's boss closing in on her in a previous scene. We also know that the player's movements can be temporarily disconnected from the real world movements, as we see Z using an emotional response camouflage to be able to vent out while his character is standing emotionlessly still.
The full-body immersion rig/hamster-ball helps you stay still in the real world while moving in OASIS. The people you see on the streets aren't using one. This has 2 main explanations.
The film makers wanted to show how OASIS players were reacting. We can essentially understand that there are really millions of people connected and everyone's in a frenzy for this final battle.
Unlike the book, the movie does not show anyone connecting with classic keyboard, so everyone is probably using the VR headsets. With this in mind, not everyone can afford the full-body immersion rig/hamster ball, so it is reasonable to assume that you can disconnect you movements if you notice you're about to hit a wall, or control you character (like turn him) without moving in the real world, only with your haptic gloves or voice commands or something.