I found this the other day as well. It actually only applies for certain browsers. I think they are doing the redirect via user-agent. Orion Browser (by Kagi)

I found this the other day as well. It actually only applies for certain browsers. I think they are doing the redirect via user-agent. Orion Browser (by Kagi) can still access i.reddit.com. This is the only way I will use mobile reddit. I don't need an app for something that can be a simple, clean web page.