QA is never a priority until you start having outages every week in production, normally around series A if someone in the engineering has a quality mindset or series B if clients churn because of unreliable product this starts to be a concern.

QA adoption within engineers is cultural and it takes time to mentor people, create processes, and adopt those processes, in my experience the tech side of it is the easier part to put in place.
Helps tremendously if the CTO or VP empowers QA from early on.