If you are satisfied, there is no need to switch. There are some reasons to consider it.
Photoshop is a stronger platform for photo editing and there are tons of resources for getting good with PS. There are videos on YouTube, some of which are pretty good, plenty of forums, books, paid videos, etc. Some of your skills will transfer, but time invested in learning PS will grow with you more than Painter skills if you decide to get more sophisticated in the kind of editing you do.
Affinity Photo is another option which has most of the PS capabilities, works similarly, is less expensive and is in many ways easier to use. And is more powerful in a few ways.
Personally, I use PS and am fairly serious about post processing. I also bought Affinity because it is reasonably inexpensive and I want to support their efforts. Competition is healthy.
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