Export dialogs show it as an option to embed the colour profile, and web export presets sometimes leave that option off to save a little weight. A file without a profile is read as sRGB by most software. That is harmless when the file really is sRGB and wrong when it is not, which is why converting to sRGB and embedding the profile together is the dependable setting.
Image editors offer two different commands, and mixing them up is the usual mistake. Converting to a profile changes the numbers so that the colours stay the same. Assigning a profile keeps the numbers and changes what they mean, so the colours shift. Deleting the profile from a file that is not sRGB has the same effect as assigning sRGB: the product changes colour without anyone touching it.
Channels treat profiles differently. Some read them, some convert every upload to sRGB, and some strip them or do not support custom ones. The only state that survives all of these is a file whose pixels are already in sRGB. A profile named after a printer, a paper or a monitor model is a sign that the file came from a print workflow or was tagged by mistake, and it is converted, not deleted.