If you're just doing video demos it's perfect to combine that with OBS for screen capture and voiceover recording while editing. The three tips I have for doing something good enough are to write a script (and rehearse it for tone/time), use a good microphone, and turn off your AC/fan when recording and listen for interference or noise when you do a take (adjusting or redoing as needed).
If you're doing live videos, hire a videographer. It's an art, really.
The next tier up is to hire an editor, pay someone for any intro credits/title roll graphics, and to let them do their thing. There are tons of services out there these days.
Also ask around. If you're in a major metro area there is probably a filmmaker community or wedding photographer that moonlights doing corporate or YouTube work. They're around!