that would be renaming the file extension but keeping the same format opening it up in an app that breaks it totally, then saving that and sharing it with a Windows user and spending an hour with them trying to make it work because they have to see it!!!!!
You know who used to do that? Microsoft Teams. I would take photos with my phone and upload them via Teams, Teams would display them just fine but saving them teams would name them .png (even though they were jpeg) and I couldn't open them with the gnome image viewer (this is also how I found out that the image viewer prioritizes extension over magic byte (which seems stupid to me).
What's always missing is nomacs - the best image viewing and light editing toolkit app on linux.
Nobody ever mentions it. Why is that? Why? It supports all the formats. It has the best slideshow options. The UI is as minimal or as informative as you set it to be. WHYYYYYY DOES NOBODY TALK ABOUT IT??? Who paid you to be silenced?
I used it for a long time years ago and it is indeed very great. But its only maintainer stopped around 2021/2022 because he got a new job or something along that line. As far i see he partially returned later but is still looking for more contributors. so the future of the project is not really secure. e.g. see https://github.com/nomacs/nomacs/issues/987
For some reason it's not included in Debian Bookworm (currently stable) and Bullseye. It previously was in Buster and will hopefully again be in Trixie (currently testing).
It's missing the "take a screenshot on your mobile phone" (which drives me nuts when people do this instead of sending me the link or the original photo).
But to be honest sometimes the Google app is bugged and it doesn't let you save the image, no matter how many times you open the long-tap menu and tap on "Save image". It makes me furious.
I needed to crop a couple of images a few days ago and completely forgot about graphical editors. I spent like 10 minutes repeatedly using imagemagick with slightly tweaked parameters until I liked the crop
people hate webp but the issue is more on windows and partially on Google
Google killed jpegxl (webp but compatible) which would've made everything easy to work with, and Microsoft didn't even bother adding webp as a format which is just crazy