Just a remark on that
specific case: Object.hasOwn landed in Chrome 93 in August 2021, and came last to Safari 15.4 in March 2022. My general advice is:
never depend¹ on features less than two years old,
avoid depending on features less than three years old, and treat two-and-a-half-year-old Safari as a bigger deal than one-and-a-half-year-old any other browser, because of how Safari major versions are tied to major OS versions to at least
some extent².
—⁂—
¹ When I say “depend” I mean “break if it’s not present”. A degraded but still functional experience is acceptable.
² I don’t use Apple stuff, so correct me if I’m wrong, but I believe that this used to be the case for macOS but may be fixed since macOS 12 <https://en.wikipedia.org/wiki/Safari_(web_browser)#Version_c...>, and is still the case with iOS et al. I believe iOS/Safari 15 is still the current version on some actively supported devices.