It's a shame what a massive proportion of archival video is marred by drop-field deinterlacing. The age of interlaced television captured and presented up to sixty fields of unique motion per second, and yet so much will be preserved in only thirty progressive frames per second, often with half the original vertical resolution. Today, digital bob filter and even motion-compensated interpolation (such as yadif=1) have become computationally trivial steps in the ingest process.
I was among the first to use it when it became available in 2013, releasing my new videos in 720p60, the best my dSLRs captured at the time; unfortunately, after ten years it appears they've been resampled or frame-dropped to 30fps, so they'll need a re-release at some point when I'm able.
Or the adjustment/transcoding process, anyway; best to keep masters in original format.
This problem is so widespread that it allowed a relatively early online mass-media use of 60fps to create a *retro* effect combined with letterboxing: that of the music video for "Finesse" by Bruno Mars. By jumping into a 4:3 frame from 24p to 60p, it instantly transported you back to the 90s watching In Living Color on a tube television, and yet also taking advantage of a relatively new feature of YouTube.