I don't think there's any excuse for hieroglyphs. Even a low-end 5 year old phone like the moto e4 has a 1280x720 display; there's plenty of pixels available to label the icons. Hieroglyphs are a "we hate our users and want them to know it" first design.
Hamburger menus could also frequently be done away with when you look at how many options they have. Like Gmail's app has them when it could fit the icons across the screen as a bar. And it's hard to argue that real estate was important since they put in a bottom bar for chat, video, and spaces whatever that is.
Pixel density isn't the problem, physical size is. Phone screens are small and many people have poor vision. Some even scale up the contents of their browser 25% or 50% or even 100%.
The more text you have, the more difficult it is to ensure a usable UI on small screens, let alone a good one. Don't be upset about the use of symbols instead of text, but about the use of bad symbols. Nobody needs the "play" button on a video widget to say "play" - they know what the right-facing triangle means. (Ironic because I don't know if it makes geometric sense to even say the triangle has a facing, but as a symbol it's well understood.)
An unlabeled bespoke icon is useless for everyone though, which is strictly worse than text being unhelpfully small for people with uncorrectably poor eyesight.
Put the text below the icon in whatever size you can. It's a strict improvement in usability.
> Hamburger menus could also frequently be done away with when you look at how many options they have. Like Gmail's app has them when it could fit the icons across the screen as a bar.
Just cracked open Gmail to check this. In the hamburger side menu, there's 18 items not even counting labels. No shot you fit this across the screen as a bar.
I was specifically looking at when an email is open. There's 9 menu options. Move To and Change Labels do the same thing, and it has a UI element on screen already. There's also Mark Important which is apparently different from star. Consolidate Move To/Change Labels and move help to the bottom, and everything should fit on top.
Then there's another menu below that with 8 items, 4 of which also already have UI elements. Give the other 4 icons. There's plenty of space on the show pictures line.
You need a menu for label filtering since the user can create many, but let's look at settings. There's a mostly blank screen with a ... menu with 2 options (why is it sometimes hamburger and sometimes ...?): manage accounts and help. Just put them on the screen. Now look at general settings. Enough stuff that I have to scroll, but for some reason 4 of them are in a ... menu. Two are the same as the last screen, with clear search and clear picture approvals added. Now go back to settings. Suddenly settings has all 4 options in the ... menu! The hidden options on the same screen are different depending on where you were before, when they could all just fit on the screen.
In general, scrolling is much faster than clicking on an icon. Lots of web UIs (e.g. navigation menus) could benefit from just putting the links at the bottom.
I like having greater content area by default, and the text next to an icon in the Gmail Android app is nice too. (The spam button, with its explanation mark, could easily be mistaken for an important button otherwise.)
It's one of the reasons I prefer how Vim and VS Code look over Intellij and Visual Studio standard. Let me better see what I'm focusing on without distractions (the content) instead of shoving a gazillion buttons on your UI in the default view.
Edit: I was too harsh about Intellij I think. The old UI I was thinking of doesn't look bad in my opinion, but I still think I would have enjoyed my experience with Visual Studio more if it had a stronger focus on content (the code) visually.
I deal with some legacy web apps and ticketing system at work. They could use a hamburger menu or two. 10 buttons, 15 tabs, and a million inputs most people don’t use.
Hamburger menus could also frequently be done away with when you look at how many options they have. Like Gmail's app has them when it could fit the icons across the screen as a bar. And it's hard to argue that real estate was important since they put in a bottom bar for chat, video, and spaces whatever that is.