Hard agree on the database layer being the real bottleneck. I've seen teams spend weeks optimizing goroutine pools only to hit connection limits on their RDS instance.
That said, worker pools still matter when you're doing bounded work against external APIs with rate limits or when you need predictable resource consumption in production. Not for throughput, but for operational safety. 10k goroutines doing DNS lookups is different from 10k goroutines sitting idle.
For most CRUD services though, yeah, the stdlib http server with context timeouts does the job. Keep it simple until you actually measure the problem.