I have much the same problem, myself. Just yesterday I dug up a small dead tree and replaced it....then potted up the dead tree in the hopes it might magically come back to life at some point. I have no space for it if it does come back to life. But still..
My saving grace is that I have found I can give stuff away, as long as it is alive when it leaves me I feel I have done my job and I can move on, like it was a child who has just left home to live elsewhere.
I have also taken up 'guerrilla gardening' which helps me get rid of non-invasive things I no longer need. Oh, and the Nextdoor app is fantastic to advertise free stuff for neighbors to come collect, even from a few towns away.
But yes, this is a problem I have. If it is alive, I can find a spot for it somewhere. Of-course, when you break up a hosta clump into 20 bits that can be a challenge sometimes.
I guess perhaps I was brought up to be frugal, and always finish my plate before leaving the table. The idea of wasting something is abhorrent now it has been drummed into me. I guess I need deprogramming, too.