It's also really easy to have high quality audio! The author recommends a "podcasting" microphone, but a $35 standalone headset mic[1] is almost as good and much easier to use. If you want to hear a comparison, I got kind of obsessed with this problem at one point and took some comparison recordings here[2]. (You need a standalone mic since most headsets, even really nice ones, have really bad mics because most heads…
Another thing people forget about is the noise canceling and other filters that are applied to your audio by default. If you're in a reasonably quiet place, it's probably reasonable to put "noise canceling" in Zoom on low. This will make your audio less garbled. If you have a really solid audio setup with headphones, you should try turning on "use original sound," which can make your audio really nice (unfortunately not available in Linux).
I highly recommend Fifine's mics. They have a USB condenser mic with a boom arm for $60 (~$35 for just the mic) [1], and a lavalier (lapel) mic for $20 [2]. The audio quality is really quite impressive.
[1] https://www.amazon.com/FIFINE-Microphone-Adjustable-Instrume...
[2] https://www.amazon.com/Lavalier-Microphone-Cardioid-Condense...