"The mist is too thick. I can't see more than 2 feet in front of me."

It might be bad weather, or night time, the mist is much thicker during these times. Sleep or wait out the poor weather, like every other biome.

"The wisplight doesn't help enough and my visibility is still bad."

As above, or learn a small amount of patience.

"The mist is always present are never subsides."

See the first answer. It actually does subside quite a lot during the day.

"The wisp torches also aren't effective and also make easy targets for enemies"

No comment, I found no need for them so haven't used them. This may be a fair point.

"It's too much of a chore to farm wisps to make torches"

Spending 10 minutes pushing a single button is a chore?