I agree with the recycling idea in general but I draw the line with smartphones, tablets and computers.

If you using smartphone only to call, text and watch YouTube, it is a minor matter to use an old phone.

If your government and bank wants you to use apps, an old smartphone is a time bomb. If you are lucky, sometimes the government bothers to try to make things backward compatible. If not, you will find that the old app no longer works and the old smartphone can't install the app.

That is why when I buy second hand tech, my favorite shop always insist that I install all the apps first before I fork over the cash.