As much as is isn't true, it really should be and I agree with you 100%. The current divisions don't make a ton of sense, and that's with Phase 2 as well (it ends with Ant-Man instead of Ultron).
Spider-Man: Far From Home is an epilogue to it all. It also acts as a sequel to Spider-Man Homecoming and sets up Peter’s next adventure. The film does address the “blip” and death of Tony Stark, so it does act as a conclusion to the Infinity Saga, therefore Phase 3 too.
