If Knative is more self-hosted FaaS than PaaS, that explains the core use case for Apollo; a traditional 12-Factor App PaaS for Kubernetes/Docker-Swarm. Knative supports a Serving Spec for routing (like AWS API Gateway) but doesn't seem to have buildpacks for 12-Factor App frameworks, as far as I can see.

Apex Up [1] deploys web apps on top of AWS Lambda using Amazon's API Gateway as the RESTful routing proxy. Maybe something like Apex Up is required to transform Knative into a PaaS for historical 12-Factor App frameworks. ZEIT Now 2.0 did the same thing for Serverless (Cloudflare Workers only?) but the company has been renamed Vercel and has pivoted around Next.js.

[1] https://github.com/apex/up