It all comes back to how Meta makes its money - data collection.
Facebook is in a really tricky position right now. They don't control the hardware or OS that it runs on, or the app stores. That means that at any time, Apple or Google can screw them over and deny Facebook from collecting data.
However, what if they had their own hardware (Oculus) running their own OS? Then, they could collect as much data as they wanted without any interference from Google or Apple. That means significantly more profit! There's no way in hell they're going to break into the mobile phone market, so VR was their best option.
That's why they pushed VR so hard. They need it to work because otherwise they have no control over their main source of income, and the squeeze on them is getting tighter ever day.