Deep dungeons in general can be done solo if desired.
The relevance of it is that doing it solo allows you to:Even if so, your reply confuses me. What does this have to do with the issue at hand? Why can't we just have sliders before getting in? There has to be design reasons behind.
- Not have to deal with prog liars.
- Allows you to practice alone and become good enough to not be a burden when you finally do join a party.
I do think that having a requirement to farm offerings somehow (even if it's people who sold it on the market board that did so) has a place, because an issue with deep dungeons currently is getting people to even queue at all. The weekly gating will help, but it also helps if they are given a reason to go back and do some of the previous floors to help people get through them. Being rewarded some offerings makes it not a complete waste of their time.
Also, I think you don't lose them unless you actually succeed and clear the boss.