I think the key problem with "stuff" is when "stuff" starts running your life and dragging you down.
People clearly have different thresholds for too much stuff, but there is one universal indicator for when you definitely you have too much stuff: You have too much stuff if you can't "put everything away".
By "put everything away" I mean be able to put everything away and then later find it without rummaging or unpacking boxes. It means having tables with nothing but permanent fixtures on them and shelves where everything is visible at a glance. It means, often, that getting new stuff means discarding old stuff to make room.
It takes a long time to get to that point, but it looks great and inspires creativity.
People clearly have different thresholds for too much stuff, but there is one universal indicator for when you definitely you have too much stuff: You have too much stuff if you can't "put everything away".
By "put everything away" I mean be able to put everything away and then later find it without rummaging or unpacking boxes. It means having tables with nothing but permanent fixtures on them and shelves where everything is visible at a glance. It means, often, that getting new stuff means discarding old stuff to make room.
It takes a long time to get to that point, but it looks great and inspires creativity.