These threads are annoying - assuming all cyclists are the same, that cyclists aren't pedestrians too & also no consideration for how it may feel to fear for your life on a bike due to behaviour of motor vehicles drivers who can kill you in a moment. Then of course the tax arguments get surfaced, with loads of misinformation.
I cycle to work daily in London & also use my bike for other errands. Cycling in the capital has become a lot safer in recent years with more segregated infrastructure, 20mph on almost all roads & more cyclists (safety in numbers) but I still experience regular close passing (which is incredibly scary), drivers blocking the advanced cycle box and a lack of giving way to cyclists going straight on at junctions by drivers who want to turn (sometimes it's as if the drivers simply do not see you).
Like all other cyclists I am also frequently a pedestrian and do sadly experience some poor behaviour of cyclists. On one crossing en route to my kids school, cyclists often jump the lights, and I've had some hairy moments there when my kids have nearly been hit by a bike. I often shout at these cyclists and a few of them act so entitled, that they are in the right when they clearly aren't. HOWEVER, while many cyclists jump these lights not all do. I never run red lights when I cycle and always give way at zebra crossings (I go over one on my route to work and witness cars not giving way far more frequently than cyclists).
Now let's get onto tax. There is no road tax, money for road maintenance comes from general taxation so cyclists like everyone else contributes. VED & Fuel Duty are charged (at a far too low rate IMO) as a way of getting drivers to pay for the massive externalities caused by driving (ie when you drive a car you pollute the world around you, impacting on others, you should pay to mitigate against this).