>>5131798You sound legit autistic, so I'll try and explain.
"Sharing" in terms of social media is not literal "sharing" in the sense of sharing resources etc. It's just called "sharing" because in the formative days of social media, the powers that be decided to use that word (eg on facebook, the button to repost something is literally called "share." The same button could have just as easily been called promote/clone/repost/etc, but as a website geared towards facilitating social interaction, the social connotations of "share" was preferred).
It's similar to how simply talking with someone openly is called "sharing," even when no resources are being exchanged, and the "sharer" is probably getting more out of it than the person being "shared" with. Like right now, you're "sharing" your confusion with us.
For hobby artists, the motivation is usually to get compliments so they can feel good, constructive criticism so they can improve, or to socially engage with people who are interested in art like they are.
For pro artists, the primary motivation is generally to build their target audience and increase their client/customer base. The hobbyist motivations also feed into it to a secondary degree - praise motivates one that they're on the right track and gives them the joy to keep going, constructive criticism allows them to keep improving their art and social media strategy, and networking with other artists gives them easier access to things like constructive criticism, as well as further art resources they may not have previously known of/had access to (knowledge of/invitation to events/classes etc, invitations to relevant things, introductions to other artists, being recommend to a fellow artist's client overflows, etc)
I'm not sure why you've narrowed the concept to altruism/egotism. Even if one were to "altruistically" share their art, would it not be egotistic of them to presume their art has the power to benefit people, and to take joy from that thought?