TFL Rail, the Eastern half, Romford, Chadwell Heath etc. To be fair, it got better on the central line. This was mid day not commuter rush. I do think East London is pretty poor at compliance culturally...
This is my observation too. Compliance varies across different parts of London. I was quite surprised to be the only person wearing a mask in a busy Tesco Local in East London several weeks after they were first mandated. In comparison, in far South East London it's unusual to see someone without a mask shopping.
The train i catch in SE London is travelling from tier 3 (Kent) to tier 2 (tiers as of the last few weeks). Despite travel out of a tier 3 are being 'advised against', the train is busy, 1/3 of people not wearing a mask, 1/3 not wearing it correctly, all the windows closed because it's 'cold'.