FYI integrating third-party services is often difficult, time-consuming, and has high maintenance costs since they often change over time or break things without warning. It's also absolutely endless - there are an unlimited number third-party services you could argue we should implement. Since we're a small team I think our resources are generally much better spent on working on the core product, except where there is an extremely compelling case (e.g. Instant Games - and even then, that's been a ton of work and already had significant ongoing maintenance cost that is delaying other core features).
In short I think we will always treat suggestions along the line of "integrate third-party service XYZ" with some skepticism and reluctance. The plugin SDK is specifically designed to allow other developers to integrate third-party services - that's what it's there for, and provides an alternative option if you really need a feature that is not already supported.