That’s not always a possibility. See for example:
https://www.theverge.com/2020/5/20/21262302/ap-test-fail-iph...
Those people didn’t need or want Photoshop or a complicated program with tons of options to convert image formats form anything to anything. Even a simpler app like Preview implies knowing where to look for the conversion part and which format to pick. They could have done instead with a simple window which said “Drop File Here”, and if it’s an HEIC, convert to JPEG. Could even have an option to delete the original, but that’s bout it.
There’s an Alfred workflow which is basically that. It does have some configuration, but the defaults are sensible and doesn’t let you screw up the important part of “detect this format which is causing me trouble and produce a format which will work”