Perhaps I due to my lack of knowledge, but to me hosted channels seem like a great tool. Users can fund their wallets without an on-chain fee, which could be prohibitively expensive at times. It's not a solid as on-chain security, but there are ways to make the risks very low.
One use case: there's a way to use this mechanism to connect a Lightning network node on Liquid with other channels on the main chain. If I were to guess, i imagine all these tools can be complementary to each other. Perhaps if fees go really crazy in the future, there will be more incentive for developing these things.