Uhm.... its not hard to figure out how to one shot kill things at low level.
And there really is no reason for any mid-high level to enter the ML crypts for example, the Viccar's caps grow elsewhere, or they can easily hire people to bring them Viccar's caps
Funny that you mention that - i just thought about this moments ago and came to the exact opposite conclusion.
I can think of... 5 places in barovia where viccars caps grow.
One requires a party and provides a medium harvest of caps.
One is easily doable, but provides just a little harvest due to the size.
Same for another, which is the most remote one.
Another one ist quite a way off and provides the smalles harvest.
Well, and then there are the ML crypts. Large and quite a good harvest.
And that is only viccars caps (well, and grave mold and ghost caps).
The ML crypts are EXTREMELY attractive as a source for crypt mushrooms.
Besides that, i noticed recently that there is another factor that makes soloing in such dungeaons almost essential for herbalists.
It is almost impossible to buy herbs for independent herbalists.
They are either collected for friends (solution: get low level friends. Ha-Ha)...
or sold to the vardo. With the current competition there is almost no alternative to make excessive herb-runs at all - including dungeons.
And in case you are not aware of that - it is not really realistic to assume that a group would be willing in a long journey that is mostly focussed on herbs.
Sidenote: Where the heck did the grove with the dread treants move to??? Or is the transition bugged?