Sorry about that, I didn’t know how to copy and paste the results from htop, so taking a screenshot was the only thing I could think of.
I added the output of the inxi to the end of the opening post.
If I’m to believe my specs, I have a 6-core CPU, an Intel Core i7-8750H, with apparently 12 threads. Looking at the screenshot, it does appear as though htop displays all 12 threads. It’s possible that OBS Studio only shows one, but I wouldn’t know. Using the System Activity Monitor (Ctrl + Esc on KDE) also shows OBS with just 1 % CPU usage, which just further confuses me.