Isn't it weird that acceptance rate is a thing we look for in a conference/journal?
Publishing a paper should not be competitive like "we take the top 20% paper", it should be "we take all papers that are good enough according to our standards". Sometimes it can be a very low or very high number depending on the quality of the paper submitted.
It's also interesting to note that rejection/acceptance rate has no correlation with the Journal Impact Factor™ (but then JIF is also a rather silly and dubious calculation too, so I'm less certain about what the non-correlation really tells us. Noteable nonetheless, particularly for JIF-worshippers of which I am not one)