Yes, it's likely the cause.
I wasted a hell of a load of time doing similar - thinking my code or query was wrong when, oh no - the infrastructure is just dead.
Running a node wouldn't help /much/ with this - it was the core identity, graphQL, jwt and media that was the problem - (currently) a single point of failure across all nodes.
For standard API queries (txns, posts, users, etc.) yes - it'd help - but you can just swap across to @desocialworld's API for example (MUCH more reliable than the core nodes have been)
That's why it's important @nader / @mossified / etc. accept, own it, acknowledge and apologise - it's affected every node and every app... think @desofy was down from Friday through to a few hours ago (bet they're delighted!)
...yet they can't spare 30 seconds to post an update or apology.
This is nice:-)