Yea part of the motivation to create Ory Kratos was that Keycloak was too clunky and cumbersome for us to use, also hard to scale and a bunch of other issues - so we wrote our own basically.
(i work for Ory as DevRel)
(i work for Ory as DevRel)
It says "When deploying Ory open-source Servers, protect access to their APIs using Ory Oathkeeper or a comparable API Gateway."