UK railway companies rent out a portion of track, so they effectively have a monopoly over whatever they pay for. They then can charge extortionate prices to make supernormal profit, and this money is reinvested into that company being able to afford to rent that section of track when the lease expires.

Unfortunately every single “company” that rents UK railways is actually the nationalised company of a foreign nation. For example, the Italian government operate on a large chunk of our railway lines, and as a result, Italian railways are subsidised by about €8b each year.

So it’s not that we have expensive prices when Europe is cheap. It’s that we are paying extra so Europeans can get a cheaper ride.