I feel like screenshots every 2 seconds would take more space than a full screen video capture.

It does! I ran into this issue (disk filling up with screenshots) and realized that the optimal compression solution already existed and was called a video file, so set up a script to run on cron to convert the folder full of pngs to a mp4.

What size differences are we talking about here? I took one screenshot (+webcam shot) once every hour for three years and it takes up around 5gb for 14,000 images. I believe I compressed it slightly some time ago.

Yeah, TimeSnapper takes them every 5 seconds, so I'd get 5-10 thousand images per day, about 1GB per day depending on quality settings.

I appreciated the (relatively) high frame rate because I enjoyed watching the timelapse at the end of the day, as a kind of review.