I think the fear of not having enough memory palaces is something every beginner has (had) at one point or the other.
I know I did (saved some “good” memory palaces for years because I wanted to put in it only things “really important”)… I shouldn’t have worried.
What I feared (not having any usable memory palaces anymore) never materialised. I don’t think I heard of anybody that truly had the problem (and not only anticipated the problem).
In a way it’s like saying “I don’t want to write about this idea, because when all my good ideas are used up, I won’t have anything to write anymore” but when you write anyway, so much more new ideas come! We are limiting ourselves with our fears.
Maybe this thread can help: The Big List: Location Ideas & Inspiration for Memory Palace Places
Also I think Anthony Methivier has an episode of his podcast (magnetic memory method) about it - I can’t find the title anymore now, maybe somebody else on this forum will know.