FFMPEG (Requires programming knowledge but very good), free, as it is specific to what you tell it to do; other editors can mess with frame rate, file type, label(s)?
FreeVideoJoiner: Its sole purpose is that; a free video joiner. It comes with FFMPEG, but the idea is you use FreeVideoJoiner and combine the video without knowledge of programming, and using a command prompt is not needed.
Avidemux (Needs a little knowledge about file formatting, but reliable)
Kapwing (possibly), simple GUI with good support. However, I'm using it right now. It may be resource heavy. Like card editors, it's WYSIWYG, and may be enough if you don't want specific encodings. You have to have an account/Google Account to remove the watermark, but as far as I know it's free? I prefer it over Windows Movie Maker which can be slow and have bad encodings. Resolution was published for me as 1280 x 780, which is not perfect; and for older Pokémon games it tends to stretch anyway? However, that can be a problem if you have lots of text and it is small.
Bandicam (unsure specifics recently. You may have to pay, or you may have to have a watermark on the video. Otherwise, it can be a good screen recorder and setting up recording audio from the computer has been lots simpler in personal experience, where Stereo Mix can sometimes not work with other tools)
VisualBoyAdvance video (not all versions of VBA may have it so you may have to find a specific build), WAV recording, BGB audio recording and frame dumper, which can be combined into a video https://code.google.com/archive/p/vba-rerecording
Good, but outdated, buggy:
Debut (Dazzle DVC-100); paid, but for streaming old consoles, etc.