Gmail is always fooling around with its layout. Some changes are good. Some just annoy.
For example, I frequently filter a lot of my email directly into folders, unread. When the number of unread messages mount up, I can easily go to that folder and do a quick check. That’s just one use of folders. They’ve traditionally been listed in the left sidebar for easy access. The new desktop version of Gmail reduces the width of the left sidebar so that you don’t see the names folders until the list pops out when you move your mouse to the sidebar. That’s a nuisance.
But that pop-up approach isn’t good enough and you’d like your labels to be visible without mouse action, tap on the three lines in the upper left of the screen (I’ve seen this referred to as a hamburger) and you’ll get the wider left sidebar back.
Believe it or not, this info required a hunt so I figured it was worth a post.