Taxation is not fundamentally unfair, it is just the most effective method of ensuring those who gain the largest benefit from wider society contribute the most back to it. There's certainly nothing immoral about us democratically deciding to pool together our wealth to run public services at a lower overall cost than the aggregate of private provision, which is what most taxation is. And in my opinion it isn't unfair that high earner pay more than they directly get out, because they benefit indirectly from the provisions - their wealth relies on the labour of us and wouldn't be sustainable unless those working in lower positions in the same business had access to health, education, transport and other facilities. It's about putting the collective good of the nation above what might appear to be in a single inidividual's short-term interest, and that's a good thing: if we abandoned taxation and with it the state, nobody living or doing their business in Britain would benefit.
Jesus christ, why do people say stupid things like 'taxation is theft' and 'property is theft' without acknowledging that both of those statements are predicated on philosophical beliefs which are decidedly unpopular?
The problem is the notion of theft is itself predicated on the notion of property, so property is logically prior and cannot therefore be theft as a matter of definition. I wouldn't object so strongly to 'property is appropriation' or something like that, but it's not as catchy.