If only 3 words wasn't a proprietary black box, which demands that you use their service / api and that you are not allowed to reproduce it without their assent. Plus there's a bunch of other drawbacks to w3w if you just search a bit online.
At least the algorithm for plus codes is known and can be reused even if Google decides to drop it in the future.
A system that depends on a functioning proprietary API to resolve coordinates is idiotic. That’s so unreliable that it can’t be used for anything more than an ephemeral exchange. At that point you might as well have a 3 word url shortened link.
There comes a time when a format has so many confusable variants, it’s best to make a new unambiguous format.
I prefer “three words”. You get three words and they identify a location suitably accurate for navigation. https://what3words.com/