You don't see meat eaters trying to make their broccoli taste like hamburger patties. Vegetables are supposed to taste like vegetables. They're good without needing to be processed. Nobody wants to buy uncanny valley meat substitute, except as a novelty. And novelty business models work, but these guys misread their market and thought it could be a daily meat replacement, for a group of people that don't eat meat, or…
There's definitely a niche for this, and it's large enough to build a multi billion dollar company.
And if it can work in the country that's home to the Currywurst, then it can work everywhere.