The "issue" with QuickTime is that it's encoding the video while you're recording, making the resulting file small enough by using some of your CPU power.
You may want to find something that doesn't encode (or doesn't encode as well). But, you'll then have to encode after recording.
Not sure if this one is faster, but I heard it being recommended by some: https://getkap.co
If you're just looking to make something quick and easy, and it's not something you think would expand into a much bigger idea or project, you could just go ahead and consider writing such an application in Electron given you say you're a web-dev. It's not going to feel 100% fluid or native or tie into many different macOS technologies correctly, but it will also give you the possibility of Windows support if that matters. I think the best Electron apps do a really good job of disguising themselves as being one, but I can always spot one from a mile away. For instance, Kap is a tool I use quite a lot for screen-recordings, but it's not a native app (open it's Preferences and you'll see what I mean).
If on the other hand you're thinking about jumping more seriously into macOS development, there's lots more iOS related tutorials/videos/books/resources that can help you at least get started with the different concepts. macOS development is not as straight-forward as iOS in some cases, and there's a lot of legacy code still laying around in the frameworks which was removed or was introduced much more cleanly in the iOS frameworks, but design patterns and basic concepts of Interface Builder and Xcode usage would be by-and-large identical between iOS and macOS projects, so you can always refer to introductory iOS material too.
Videos: https://medium.com/macos-app-development/100-days-of-osx-development-e61591fcb8c8
Books: I’d suggest the Big Nerd Ranch books if you’d prefer books. It’s how I got started on Cocoa programming back in 2003 with the “bible” from Aaron Hillegass. They seem to have screencasts too, which might help summarise the best parts of all the WWDC videos over the years.
I suggest looking at Kap by Sindre Sorhus:
https://getkap.co
The combination of throwing off images as well as videos can be done in the processing window after your recording where you can save frames from your video form specific places in said video if you just move your slider neck and neck and export as APNG from the dropdown menu.
I don't use SnagIt and I rarely use anything else than the built-in screenshot tool that Apple provides with macOS Monterey.
If I go really wild I would use Kap / Gifski
Have you tried Quick Time? It's cool and frêèêëēėę
Otherwise, what you recording for? macs itselfaren't that feature-rich in self recording. if you plan gaming or especially want to record system sounds, you need to have things installed
Also, here's an free alternative, with lots of supporting extensions
Kapucino: https://getkap.co/
I use Kap^[1] for all my screen recording needs which is one of the many great apps Sindre Sorhus^[2] has had a hand in creating. I'm not a recording power user though, so maybe it's missing features that streams or YouTubers may need, but it's definitely packed with a lot right out of the box. And there is even a plug-in system for extending its functionality even more.
I love the simplicity, the developer, its ability to share my files with external services quickly via plugins (I routinely share my recordings with his other app Gifski^[3]), the fact that it's open-source, and the fact that it's free. IMO it's well worth checking out.
For my product, I mainly use https://getkap.co/. The quality is great and it offers many editing options.
You cannot zoom though. Maybe you can zoom on a specific section by using Adobe After Effects.