You’re forgetting amortization. You can’t copy a video file to a drive and expect it to last forever. It requires energy to run and the drivers break down over time. Google is one of the largest consumers of HDDs and SSDs in the world. Plus you need to pay engineers who maintain the whole thing, pay the finance team to make orders, etc. And then you have to have recycling and logistics. I bet they dispose of the whole truck loads of old drives every day, you can’t put that many in your recycling bin and call it a day.