I exclusively breastfed my DS and waited until he was 6 month old before introducing solids.
I found everyone was pressuring me to start solids earlier to 'help' his sleep and because he was interested in food. I waited mainly because I wanted to follow baby-led weaning, meaning they need to be able to sit-up well and grab/grasp food.
DS is now a much better eater than any of the babies around his age. He didn't suffer at all by waiting that little bit longer. Eating didn't improve his sleep at all!
Do what feels right for you and your baby. Breast milk is much more calorie dense than food so there really is no need to start solids early unless you want to. Food before 1 is just for fun