To assure Bitcoin remains decentralised, blocks need to remain small enough for anyone to run a full node.

How does this then co-exist with the increasing block sizes on Segwit (1X)? There are now block sizes above 1MB. I saw 1.6MB the other day.

Doesn't this notion counter decentralisation?

I'm curious to learn more about the block size under Segwit, any pointers appreciated.