I think it's necessary, but not sufficient. So I kinda like my better:
It's art if (and to the extent of) people generally agree it's art.
Sounds tautological, but it isn't[0].
Of course, not everything is art. There are some aspects typically - but not always - present. Whether something gives you an emotion is one. Whether it has a deeper story behind it is another. Whether it's something that you can bond over with other people, or a shared experience, yet another. But none of those are required to be present. Art is ultimately a consensus opinion.
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[0] - In fact, most of our civilization is built on ideas that exist only as long as most people expect most other people to believe them. Examples include: money, laws, countries, corporations, even the concept of society itself.