Huh? I would LOVE to be the next Japan, as opposed to the next South Africa, Israel, India, Philippines, or Brazil.
Because with the massive demographic changes caused by immigration into Europe, they are ensuring unending ethnic conflict. The best they can hope for is that the different people can carve out their own enclaves and leave each other alone, only having small wars flare up occasionally.
The problems that Japan is facing are a BLESSING compared to the rest of the 1st world.
Nobody talks about the upsides of Japan's population decline. Japan is going to experience a major redistribution of wealth, as fewer people inherit more things. Land that was locked up for centuries is going to be sold to new people. Housing will become more affordable. Already, the chronic crowding is becoming less of a problem, as Japan has essentially "finished" their major infrastructure, and there are no new plans to build any new train lines or anything like that.
Something like 30% of our jobs are going to be eliminated in the next 20 years as self driving vehicles are rolled out. Even if immigration were cut to 0, we are still facing a work crisis regardless.
Does any nation really need any more unskilled or semi-skilled labor to grow? Check out this new Japanese drywalling robot: https://www.youtube.com/watch?v=n_sUJtl1V8A
The Japanese are embracing this as an opportunity to improve automation and benefit from the challenge.
Countries like Italy and Hungry are rolling out programs to offer financial incentives to people that have more children: https://www.bbc.com/news/world-europe-36297177
These are very solvable problems, but many governments are only making things worse.