I've already built my application using Apollo GraphQL (with subscriptions) and Sequelize. However, Apollo GraphQL is very unstable, no proper authentication/authorization techniques. I'm planning to use old school Rest based APIs and Socket IO.
However, I'm confused on choosing FeathersJS and Loopback. Both are top frameworks for building rest API.
Sequelize)feathers-plusIf you do or can use TypeScript, then you should check out NestJS. I'm very fond of it. It covers all of the pros that you mentioned for Feathers. Plus it also has support for auto-generated Swagger docs, which is facilitated by type annonations and decorators from TypeScript. It does not have built-in ACL support, but its concept of guards could be adapted to support ACL.
We're using FeathersJS for building big-scale eGovernance web applications. You're already ahead with a good list of pros. Apart from those, here is what I really, really like about FeathersJS:
As an aside – once you're a bit comfortable with FeathersJS, I would recommend a reading of the following article which sheds light on the inspiration behind its architecture (services, and hooks) — a mix of Functional, Aspect Oriented Programming!
Coming to the CONS you've mentioned, I would say they aren't really any cons. I want to re-iterate how brilliant the FeathersJS ecosystem is.
feathers-swaggerfor auto-generating docs of services you would build.feathers-permissionsfor simple service level ACLs. You can also amp things up a bit with CASL