Brainstorming works when you do it properly - this means not thinking about 10 ideas, but 100 ideas. Often people stop just short of creating magic, and with practice, persistence pays off.
For digital marketing, in particular, there are many ways to A/B test different headlines. Only lazy people try one and run. If you want to stand out in social media ads, the same thing - test non-stop. You can't test properly unless you have many different things to test (headlines, graphics, captions, etc.).
A little creativity never hurt anyone, and in a cluttered space (e-commerce, anyone?), you need every advantage you can get to stand out. If everyone is using the same headline, it's time to try something new and grab your audience's attention.
Thinking about pushing (sales), here are 100 different ideas on headlines.