You appear to be moving back and forth between 1. saying that art has features that makes it memorable and 2. claiming that engaging with art improves your overall cognitive ability and memory (and therefore supports the claim of the title of this post).
For example: … :
Emotional Connection: Paintings often evoke emotions and feelings. Emotionally charged experiences are more likely to be remembered, contributing to a stronger memory of the artwork.
… is about how art has a feature that makes it memorable. You make no claims about how having an emotional connection with art helps overall cognitive ability and memory.
And than here for example: …
Narrative and Storytelling: Many paintings tell a story or convey a message. Engaging with the narrative within a painting can stimulate the brain’s storytelling and memory retention capacities.
… you do the exact opposite. Engaging with the narrative within a painting can in your estimation stimulate the brain’s storytelling and memory retention capacities. But you say nothing about how the storytelling makes the art more memorable.
Another point of criticism I would like to make is, that the evidence or argumentation underpinning your title post statement is is not all that convincing to me.
For example: … :
Visual Stimulation: Viewing paintings provides visual stimulation that activates different regions of the brain. This can enhance overall cognitive function, including memory.
You appear to be making the claim (correct me if I am wrong) that any kind of stimulation of different regions of the brain enhances overall cognitive function, including memory. If eating a pizza also stimulates different brain regions, than it also enhances … by your logic. In other words you are more or less making a claim about the specialness of art (as a way to enhance …) that you don’t support by any evidence or argumentation.
I have made very similar pizza related 
comments in this thread: “Why music causes memories to flood back”.
1st quote from “why music …” :
Evidence also exists that music prompts the secretion of brain neurotransmitters, such as dopamine, a chemical messenger that plays a role in the brain’s reward/pleasure system.
My response was:
Everything that’s fun causes dopamine secretion I imagine, like social media, gaming, movies and eating pizza. Seems like “water is wet” kind of a discovery.
So the above response was not just also about pizza ( as part of a counter argument), but I was arguing against the claim of specialness of music (just as with the claimed specialness of art).
And a similar 2nd quote:
“Music activates different parts of the brain,” making it an especially versatile tool,
My reponse:
How many parts are activated by eating pizza?; if the answer is more than 1, it also qualifies as a versatile tool by this logic.
I would like to finsh my repons by focussing on another simularity between your post and that of Why music causes … .
Art Therapy: For some individuals, art therapy has been shown to improve memory and cognitive function. Engaging in artistic expression as a therapeutic activity can have positive effects on mental well-being and memory.
Brings back memories to this part of the other discussion.
3rd quote:
Melissa Owens, a music therapist at Virginia Commonwealth University Health, already has seen this in her work. “I still find myself in awe of music’s ability to positively change behavior, emotion and even the relationship between a caregiver and their loved one, if even only for the duration of the specific song,”
My repons:
It would be a surprise if she said that what she does for a living is quackery.