Why not just use Istio and Knative? Also Project contour can do the same as an api Gateway. What's the difference?
Disclaimer: I work for Solo.io
An API Gateway can do sophisticated edge security challenges (OIDC, Authz based on OPA, web app firewalling/WAF, etc) as well as things like message transformation, swagger/grpc detection, exposing APIs for self-service signup through a portal, etc. Gloo does all these things.
I've written in depth about this as well, specifically in terms of things like contour, Istio ingress gateway, consul's service mesh gateway, etc, etc
https://blog.christianposta.com/microservices/do-i-need-an-a...
Gloo resources: https://docs.solo.io/gloo/latest/guides/dev_portal/ https://docs.solo.io/gloo/latest/guides/security/waf/ https://docs.solo.io/gloo/latest/guides/security/auth/oauth/... https://docs.solo.io/gloo/latest/guides/security/opa/ https://docs.solo.io/gloo/latest/installation/advanced_confi... https://docs.solo.io/gloo/latest/guides/traffic_management/r...
I'd say the main reason to use Gloo is it's much simpler, it's based on Envoy which is where most of the innovation around L7 proxies is happening these days (ie, see WebAssembly), and was built from the ground up with a cloud-native and kube-native architecture.
More can be found here:
https://docs.solo.io/gloo/latest/introduction/others/
And I can go into much more detail on slack. I'm `ceposta` on the solo/istio/cncf/envoy/kubernetes slack
Gloo has lots of other features, like WAF and Webassembly hooks for request flow.