Yes, using Plugshare is practically essential, even for Tesla stations (Destination chargers and even Superchargers), so you can get a feel for if the station is even up, is frequently in use/blocked, and what amenities are nearby. I would be very cautious about relying only on the in car nav outside of the Supercharger network.
That said, Plugshare entries are not 100% accurate either. It is mostly crowd-sourced, so generally reliable, but there can be erroneous entries there too, so if you do notice an error, do the community a favor and note it (or submit a correction). And always check in, positive or negative, so the rest of the community can get a feel for how reliable the station is.
One particular thorny issue is car dealers. Their charging stations may be nominally public, but you show up and they are openly hostile to non-customers using their charging stations. And now they have figured out that they can install stations that allow them to set (very expensive) fees for non-authorized users, so in general it's usually just best to avoid them, which honestly, I think is fine: back when the Nissan LEAF was new, a third-party charging network never really materialized in most areas, and Nissan dealers were the only game in town. But we are mostly beyond that now, so it's probably time to abandon the idea that car dealers need to provide charging for the public (really, it's a strange place to stop to charge anyway!)