I don’t think you can easily pick one as one site is focused on pictures and keeping your attention as long as possible and the other is focused on bringing the worst in humanity?mainly text and interacting with followers.
Personally I prefer Instagram. I've been growing a meme account since May 2020 and have experienced phenomenal growth. Twitter is a platform I have always struggled with and can never seem to wrap my head around.
Definitely Instagram. There is no strong limitation in the number of characters and there is a possibility of high-quality adding of visual content. Still, watch