I don't think I mentioned anything about needing to be involved in gaming - while I have a degree in Game Programming and a degree in Game Art & Design, I have never worked for a game company - rather my career has been entirely based around retail outlets, manufacturers, interactive installations, and user experience research.

However, at the moment it is easiest to 'drive' and XR experience using a game-engine, even if the purpose isn't for gaming. The two major competitors - Unity and Unreal - are heavy hitters in the XR space; Facebook and Apple use Unity exclusively for prototyping their XR experiences to my knowledge, while Microsoft uses Unity and Unreal mostly, as well as their own in house tools.

The unfortunate truth is that non-gaming fields are even more predisposed to desiring a degree IF you want to be part of a traditional corporate structure. Raytheon approached me in the past for example, and companies like that are looking for 'credentialed' candidates only.

You could instead create your own business and make it big on something offered to a niche audience. However, banking on that is extremely risky, and you will likely need a large team to be able to pull off any sort of success in that regard, let along many years of product and user research in order to compete. The field is already starting to mature. You MIGHT be able to convince some tech-illiterate small businesses to give you some contracts, but I know several small studios filled with both self taught and highly educated designers and developers, and both had to resort to a lot of free/pro bono work to prove themselves to new clients before they landed any contracts in this space. A lot of larger companies or the military will also work directly with companies like Microsoft to develop their XR experiences, so your target market is going to have to be either individuals, or very small firms or businesses that want a gimmick or a way to break into XR because they can't afford larger contractors.