How do I download videos from YouTube on my MacBook?

I personally like to use yt-dlp, a command line tool, to be operated from Terminal.

With its options [see: yt-dlp --help], you can be quite precise to which stream with what properties to get.

Without specifying options, it will get the best video and audio streams available, and remux into one container. That might be webm, mp4, or mkv. The mp4 may sometimes have codecs (e.g. VP9) not compatible with QuickTime. So keep your conversion software ready for this one, as other formats (e.g. H.264) on the YT servers could be available in lower quality only. It depends on the specific video, really.

I personally use 4K Video Downloader Plus. it starts with an endless free trial. or you can buy a one year subscription for $15 USD, or a lifetime license for $25 USD.

Of course Google won't give you a download link unless you subscribe to their premium service, otherwise no link is given because they want to control the ads you see while watching the video on their service. Despite that there are some apps that you can try that will provide a workaround to these restrictions, although your mileage may vary.

https://www.zdnet.com/home-and-office/home-entertainment/how-i-download-youtube-videos-for-free/

The first free one mentioned is the best.

You will also find that YT is now encoding its videos as .webm instead of .mp4

These don't play in many apps so you will need to google for a free .webm converter.