Almost all our traffic goes through Google, Amazon and Facebook. It's extremely centralised.
Blockchain a don't claim to have a monpoloy - they're just the most recent thing that's repopularised decentralisation.
If Amazon servers go down, so does a significant portion of the internet. That's centralisation at work!
Blockchain tech doesn't claim to have a monopoly on the term 'decentralisation', it's just re-popularised the technology.