I would never get lip fillers myself. I prefer a natural look. I think lip fillers almost always look bad, I always see youtubers and the like with them and especially when they remove their makeup it looks so swollen and unnatural.
Working out makes you healthier, that's why it's attractive when people are fit. It's a natural way to make yourself more attractive. I work out. Squat butts are better than fake butts.
I mean people can do whatever they want really, but in my personal opinion natural is always better. I would rather improve myself via lifestyle changes than by injections.