PBXRecorder and I believe the recording features in PinballX (I have not tested) capture video in a 2-step process.
The initial capture dumps raw frames into a container. It takes this approach because compressing video is a CPU intensive process in itself, so intensive that it may cause slowdown/dropped frames in the game that you are trying to capture which you don't want.
The second step happens after the capture. The video is processed to precisely cut the length to the right time (30 seconds, 60 seconds, or whatever) and to compress frames so that file size is manageable. OBS Studio and many freeware video editing suites are based on ffmpeg. In ffmepg, the crf or qp flags are compression quality level parameters in the H.264 codec (the one that is commonly used for mp4 format) that can be used to find the desired level of quality versus size in the output file. The higher the number used in the flag the higher the compression but the less quality. Even picking a value close to the middle will produce output with substantial savings in file size with an imperceptible impact on quality. PBXRecorder has a default crf value of 26, as I recall, which favors a little bit more on smaller size versus quality. This gets the target length for a full HD video, 60 seconds, to about 15 to 20 Mb. Yes, 4K would be larger but not even close to 200 Mb for 30 seconds.
Hey, but it's not my server and it's not my bandwidth. If people have the hardware and hard drive space to handle this, then more power to them.
Don't get me wrong. I'm usually the HQ at all costs guy. I look for 2000 px wide wheel images and 300 dpi flyer scans for my media. I've redrawn hundreds of instruction cards to ensure all the sources are vector-based or highest quality raster and all fonts are accurate. And I'm muttering to myself, "Jeez! Tone it down, friend.".