I agree, G+ the product was fine. Some very good things came out of it (video Hangouts, Google Photos). The push to force it down everyone's throat marked a turning point in my perception of Google and resulted in a bunch of harmful changes and loss of trust. Shutting it down eventually made sense - the brand had zero cachet and no significant population was using it. As an IC or manager within Google, there wasn't much you could do for your career by working on G+. It was a dead end product by the time it was shut down.
Okay, sure, it made sense to shut it down, but to me it would make sense to do a new one today for the aforementioned reasons (use cases).
(But of course somehow most of Alphabet is still tragicomically bad at B2C, and now YT also seems to be going down the drain with the overemphasis on shorts.)