Probably.
Most small businesses will benefit from some form of strategic optimization of their site. Some businesses, however, won't find much return on their SEO investment.
If your business meets a felt need
— "chinese restaurant near me," "best donut shops in lexington," or "how to fix a clogged drain" — you will absolutely benefit from SEO.
If your product or service, by its very nature, doesn't meet a felt need, SEO may not be the best strategy for you. Will a musician, who doesn't meet a felt need, benefit from SEO? Sure. It just might not be at the top of my marketing strategy for you.