I flew into London City Airport around 20:00 last night after spending the weekend in Germany and took the DLR to Bank for the Northern line home. Mask wearing on the DLR was around 50 / 50, though I was a bit worried for an older German woman who started remonstrating with a group of yoof about their lack of masks as they didn't appreciate her approach. Onto the Northern line and wow - mask usage on the platform and on-train down around 20% with a fairly large sample. This surprised me as I use the Northern line most days and compliance has always been much higher than this, even late into the evening.
Back in Germany, compliance was universally 100%, even at 03:00 on a packed U-Bahn with people coming back from pubs, clubs etc. Also, FFP2 masks are mandated there (with some allowances for surgical masks) and I'm extremely glad we haven't been forced to wear those here in the UK - tight, extremely uncomfortable to wear, genuinely harder to breathe, glasses constantly steamed up etc. I get these probably work better, but I won't complain again about having to wear my dirty, year-old, lightweight cotton mask that's so loose it almost won't stay over my ears!