Quarkus resteasy reactive is the default Quarkus REST implementation, but it doesn't support servlet (https://quarkus.io/guides/rest-migration#servlets). Investigate if it is possible to migrate the quarkus quickstarts to Quarkus resteasy reactive (see https://quarkus.io/guides/rest).
See the discussion at https://github.com/jbosstm/quickstart/pull/470