What will happen to competition when eth 2.0 is released?

There are many alternatives to eth that have grown solely due to eth's high gas fees. Don't get me wrong, I also use them to save on fees. But what will happen with them when eth 2.0 is released? Will they still be as popular? Will users and developers flock back to eth?

If so, isn't smart to short the alternatives and go long on eth in advance of the release of eth 2.0?