Why are my JPEG files so big?

I export my images from lightroom at full quality and they end up anywhere from 8-24mb files. Mostly ranging 11-24mb per image. I've been told that my files are huge and they especially have issues with facebook's compression. I've tried reducing the quality or size of my images through lightroom export settings according to recommendations from google searches. However, the images end up looking pixelated or blurry. I'm not sure what I'm doing wrong but whenever I trade headshots with another photographer, their files are much smaller and the quality is still great. I'm not sure if the issue is with my camera or my export settings. I was recommended jpeg mini to reduce my file sizes but I feel like I shouldn't have to go through the extra hoops to get them smaller when other photographers dont have the same issues as I do. Any ideas or suggestions? I shoot on a Fujifilm XT-3 which is a crop sensor and most of the photographers I trade with have full frame, which I would think would have bigger file sizes than mine.