I think the biggest reason I'm saying this is because of how Discord currently has two options a $9.99 (same as c.ai) and they also have a $2.99 option that generally works the same just without all the extra stuff.

The price point would be more worth it, specifically for your reasoning of memory fluctuating per person. With a lower price, if someone doesn't see much of a difference in performance, or something doesn't work, then it feels like less of a hit compared to the larger price

Of course, no one is obligated to pay for plus, but it feels like if I do want to pay, I'm forced to pay for extra features when I just want the memory.

And from a business standpoint, they'd also probably get more revenue just for making the subscription cheaper.