We don't offer swaps involving Tether and with regards to Liquid's L-BTC, well it simply enables use cases that are not possible with onchain Bitcoin. But we see your point that Liquid doesn't have the same properties as Lightning as it's not featuring unilateral exit.

We can certainly explore ways to help users understand trade-offs better, similar to how https://www.bitcoinlayers.org does.

Also, the new layers we are working on do feature unilateral exit and we are very excited about the use cases one can build with it. Namely with Ark.