Often, the greatest value of a thread comes from the comments made in response to OP.
If an initial post is worthy, it will attract considerable upvoats, so will its comments. These take time, though. Time for an accumulation of people to read the post, and read the comment. Also, time is required to sift the comments up and down, according to their merit.
A quick and easy fix to help right this would be to improve the sophistication of the "Sort by..." options. Include Sort by best over "1 year, 2 years, 3 years..." Also allow sorting posts by the upvoats their comments receive. Make this sorting available as a visible option, and it should not interfere with the ordinary running of Voat.
To assist newcomers in seeing the value of comments in Voat, it could help if people suggested Voat be read in such a way, where the comments and "best over 4 years" posts were seen as the default for a while.