I also really want to move to Japan, so I've been looking at some options. Here are some thoughts:
in my opinion, it depends on what you are looking for. From my research, if you are a gaijin, you usually have a harder time getting the same or better income than a Japanese person. There is still some discrimination there. I think the best option to move to Japan is to have your own business. Preferably something that works internationally and is not limited to mainland Japan.
no one can tell you for sure what Japan's economy will look like in 30 years, it depends too much on politics. If Japan plans to be less restrictive with foreigners and more foreigners work and start businesses there, it would be better, but at the moment it doesn't look like much will change.