I guess much like aria attributes it varies based on the quality of the product/motivation of the business.
I just tried one of my banking apps and a Reddit client and found neither provided tooltips - perhaps they thought those particular icons are too self explanatory or perhaps they didn't bother/used a cross platform tech that didn't make it easy.
Actually even on Google maps I don't seem to get tooltips for the fab icons for center map / directions.
I do remember this being a thing but it feels like it's fallen out of fashion.
Pixel 3a / android 11