People also differentiate heavily on the basis of scale and profit. Artists are often fine with people sharing their posts and may even tolerate someone asking for permission to make printouts or whatever else for their circle of friends, but will expect some sort of royalty if you're asking to be able to sell prints of their artwork on a store.

Hell, even with viral videos it's relatively common that normal people can share away while entertainment companies and influencers are expected to pay for a license.

With memes it isn't clear exactly who made the first template, and the creation of them doesn't revolve around specific people in the same way, nor are they meaningfully tied to profits.

When creators post their content online to be shared, they do it with the focus being on reaching individuals, not for it to be sucked up by soulless companies to extract all value without the intention of giving back.