If it comes to getting famous you are right. An influencer or vip should promote you or a something out your painting and indeed overnight you become without doing anything. The other option is being noticed by an art critique or some rich bored person showing off.

Being noticed consumes a lot of time and marketing (yourself) as well.
I watched many videos about publishing (the layout at Amazon shows even wrong with after the layout and using their app) and this what they say: if you publish you should be able to refer to some earlier books (meaning you need at least 4). Next you should publish on a regular basis. I know one doing well giving away one free book per month. Now we can discuss what books like but for him this works.

I am afraid that in the age of AI and to the generations raised by social media and AI handmade, true art and AI art are no difference. The average person cannot tell the difference and doesn't care.

A foundation might be a good solution (no personal income, work protected, inherence (grand) children, supporting free artists (financial or with materials), free books (paintings selected by theme and not too much text), one or two books for sale per year. Thicker, bigger..something like that.

Where did you print your other books?

You sound like me just without time to paint that much which is annoying.