Oh, my gosh! I love this idea!
I suspect professional artists may dislike the idea for the same reason they dislike AI-generated art: in a world where art can be had for free, why would people buy it? In some ways it constitutes a threat to the professional, because it may well drive prices down.
In a way I like the idea precisely
because it allows us amateurs to take revenge on the professional world in which we couldn't make it.
Incidentally, I recently ran into the work of a quite fascinating artist by name of Percy Kelly (1918 - 93). He spent much of his life as postal worker, and made art in his free time. He was good enough that galleries invited him to exhibit, but he seldom did - he liked his own work and was very reluctant to part with it!
What he did often do though was to send family and friends illustrated letters, often with the envelopes also beautifully decorated:
Now isn't that a great idea? I remember sometimes doing the same as a young man, back in the days when paper letters were still a thing. Alas, alas, no more.
I have considered sending family and friends paper letters again, just for the fun of it, but alas, our post office is one more thing that our current government has run into the ground, and sending anything via the post office is an elaborate way of throwing it in the garbage. One can use a courier, but that gets rather prohibitively expensive simply for the sake of a bit of fun.