You can only say “no” too many times before people stop asking you to be a part of something. I understand too well that saying “yes” too many times can deplete your mind, body and soul. Saying “no” frequently means giving up possible opportunities that can change your life and the lives of others.
The solution could be prioritizing ones life so that there can be some balance but even then its easy to decline instead of accept. Professionally you have to say yes every now and then to indicate you still have interest in growth and advancement in your chosen field. Personally it means giving value to relationships of family and friends that you want to be a part of their lives. Just saying “no” just to say “no” out of habit can be a problem for you down the road.
It takes courage either way to say yes and to say no. You just have to figure out what means more to you.