Well, this is a different topic, but allright. In theory, you can use a newsreader, but the problem is that some NNTP commands are not implemented in srndv2, and it's sketchy and slow when using it directly.
Over tor, speed is the biggest issue, but it would slow down over clearnet as well. Especially when posts have attachments. You simply can't glance over a thread like on the web interface, because you don't see the contents of posts from the overview of a group, threads don't have subjects. If you actually want to read the posts, it will be painfully slow because you will receive full attachments with them.
You have to wait twenty seconds for a post to appear on your reader. The posts has message "haha what faggots everyone of you" and a smug anime picture. So much waiting for so little.
Now worry not, there are ways to fix this. If you cache the posts in newsreader or have a local nntpchan node, it will speed things up. This requires much more resources than just browsing someone else's node and might be preferable in some situations, but I wouldn't do it that way on my laptop when travelling.
Then you go back to overview to see what other threads there are. Usenet is a nice thing, because of how the references work. You are able to keep track of a discussion of hundreds of posts. Well, nntpchan breaks this, so overview is mostly useless for that: all threads are flat, with only reference to OP last time I checked. To fix, we would need to hack all the newsreaders to keep track of the references that are in the messages (because they are different from the References header that NNTP provides). Which needs the reader to read all posts, causing huge bandwidth because of attachments. Or the server would have to scan the post for references and include them in References: header.
Another solution would be to load only the text message first with a special command. (I think IMAP has a partial fetch feature like that, but it never worked anywhere.) Or we could simply use NNTP as intended, using headers correctly and putting binaries in .binaries. Right now nntpchan puts all the usability to the web front-end and it will likely stay that way forever.
I don't have a simple solution for thumbnails that works for both NNTP and web clients in nntpchan. Either it's complicated, or the newsreader has to load the whole file every time.
But try it yourself. Maybe you will find a better way to solve this. Maybe this is all just autism.