Beyond I believe advertising is broken right now, I am a developer that feels confident with tools like Lighthouse and passing the basic checks will do the trick.
But it seems there is more behind. One of the major existential doubts I have is: Why are so many companies doing paid backlink checks and stealing money to the customers?
Do exist an Open Source initiative to give some clarity to this problem and reduce unnecessary costs and break the spending flywheel for normal users/companies?
Beyond backlinks, you would do good to implement fast load times and cache the resources that you can. Once you max out technically, focus on being honest and get honest people talking about your product.