A SWE who has always worked in DevTooling companies will always be preferred by DevTooling companies over a generalist. A SWE who has always worked in AdTech will always be preferred by AdTech companies over a generalist. etc etc.

Software fundamentals - though useful - are table stakes skills at this point. No business wants to deal with the headache of on-ramping employees who have never worked in a specific domain or industry because it takes too long for a generalist employee to build the intuition needed to understand that segment of the industry.