Do you believe in a) growing the proven way (data+research) or b) just testing different things?

Whether you are in e-commerce or SaaS - growing the bottom line and other KPIs is something we can not overlook. What are your beliefs on growth and why? A) Growing customer happiness, profitability, engagement, and conversion based on data, research, and psychology (block by block, such as first the product, then the marketing, then the sales, then the retention)? Examples: - Growth.design https://growth.design/psychology (very in-depth approach) - Best Practices in Ecom https://www.wunderfront.com/fixit/fix-your-shop 2) Or just googling and testing different methods, such as suggestions from blog posts (google, do, google, do, see what works)? - 10 Ways to Grow Your SaaS Startup Faster https://articles.bplans.com/7-ways-grow-saas-startup-faster/ - 20 Proven Steps to Growing a SaaS Startup from Scratch https://userguiding.com/blog/growing-a-saas/ C) Hybrid, or smth else? Curious?!