As long as you are comfortable filtering then bikes are the best way of getting around in London, or any other city for that matter. Your route would not have taken you into the busiest bit anyway, so not such an issue. There are thousands of bikes and scooters that are parked every day around London, in fact finding a gap to squeeze yours into can be a challenge sometimes on weekdays. It is inevitable some will get lifted, but in reality it is a minute proportion. It does help if you have something that isn’t the most valuable bike in your particular parking area though. I rode my bike through central London last Friday to take part in a walking football competition in Brixton and beat the team bus from Cambridge by over an hour. It can actually be quite satisfying weaving your way around the traffic.