Trees are like old friends, and it's sad when they go. As you say, the only constant in life is change.  We lost our huge walnut tree a couple of years ago. Sad after a long time of providing shade and nuts.  I did enjoy your take on your tree, and making a negative into a positive.  I bet it keeps on growing, in some form or another, those things are hard to slow down.   And using it as a frog-watching platform is a real positive.   Enjoy your aperitif out on the long limb over the water.