It is definitely difficult because every year people ask whether meteor is dying. So eventually it might just happen, but meteor keeps up with its heart beat.

Meteor is quite different from other frameworks like Express/FeathersJS etc... They tend to be more like Libraries, whereas Meteor is a full Framework, all the decisions made, packed and working for you.

Meteor is no longer as simple or as powerful. They allow you to mix and match and are becoming more of a library, but without the strength other libraries have. FeathersJS can use most if not all the packages Express can because these libraries mingle and are built off of each other. They use similar packages.

Meteor started off with its own package library which is a gonner now. Meteor uses the standard NPM now, but that loses some of the beauty of a package made for meteor, tailored and updated. But now NPM and other libraries have way more support than meteor packages did. 

For Example: Let us say you wanted to make an API call to Meteor, well, you need a package and many are no longer maintained, but you can probably find something or make your own. It's not make or break, but it can be annoying.

Why Meteor is NOT dead: Probably the best reason is the ease of use that comes with Meteor. Connecting Data in the Database to the View is extremely simple, I have seen only DerbyJS perhaps do it better. Sadly Meteor is not the best data connection but its simplicity to learn, get up and running, and be powerful is impressive even nowadays. Especially since you can create Phone Applications quite easily by converting your application with cordova from the command line.

Is Meteor Dead? Not exactly, but the lack of support to really let it duck and weave with other frameworks is hurting it. It allows for socket connections, but REST api is an important tool nowadays that Meteor does not do well, which is a shame in my opinion. Whenever I assume API calls will happen with an application I simply look elsewhere.

Meteor also appears to me, harder to make efficient for massive projects, but it is hard to tell from anecdotal evidence. I personally have not had issues, but I can imagine that it is possible to create bottlenecks.