> The competing open standard is FreeSync, spearheaded by AMD. Since 2019, NVIDIA also supports FreeSync, but under their “G-Sync Compatible” branding. Personally, I wouldn’t bother with G-Sync when a competing, open standard exists and differences are negligible[4].
Open is good, but the open standard itself is not enough. You need some kind of testing/certification, which is built in to the G-Sync process. AMD does have a FreeSync certification program now which is good.
If you rely on just the standard, some manufacturers get really lazy. One of my screens technically supports FreeSync but I turned it off day one because it has a narrow range and flickers very badly.