Tipping was never as big of a thing in the UK. Part of that is that I don't think people generally eat out as much.
Maybe it's changed now.
Sorry, but not tipping because they are not handing out menus which is a good idea right now? That sounds like an excuse to justify it to yourself.
Likewise, waiting outside - these are often rules mandated on restaurants or the view that people don't want to see tightly packed groups of people. Punishing the wait staff for it is petty and low and again it sounds like an excuse more than a legitimate reason.
You should tip more now because wait staff are facing extra challenges, often having to wear masks and wipe things down more thoroughly and more often and the volume of visitors is often less - fewer covers means fewer people who potentially tip, so make up for those people who chose to be assholes.