Because for every person like you that jumps through hops to get a new deal there are lots of people who just passivelly let the renewal happen under inferior conditions that they could have got if they tried.

That's also why they put stupid hindrances in your way: such things cause many people to give up and just go along with a suboptimal renewal, ergo they make more money from acting thus than they lose from clients who say "enough is enough" and drop them (notice how you did not drop them - they lost nothing from giving you the run around and could've gained if you had given up and renewed with the shit conditions: it's pretty much a can't-loose situation for them)

I lived in then UK for over a decade and one thing that stood out when I moved from the The Netherlands to the UK (already more than 15 years ago) and from the UK to Portugal is how much more the larger consumer-facing companies in the UK did the most that they could to take advantage of people's mistakes or laziness than in those other countries - I remember a particularly sleazy gym membership contract from Virgin were per-contract (I always read those things) the only way to cancel it before the yearly auto-renewal was to contact them during a specific week before renewal (2 weeks before end of contract if I remember it correctly), not before nor after.

Over the whole time I was there, a handful of the most outrageous abuses when it came to consumer contracts were plugged (the one I remember the best was the creation of a rental deposit insurance to stop tenants from losing their deposits at the end of the rental agreement, as before that landlords would often just keep it all for no reason and then the only option the tenant had was take it to Court) but the whole posture of taking advantage of costumer laziness and normal mistakes (auch as, forgetting a date for canceling and auto-renewal) was widespread in the UK compared to other countries I lived in.

As it so happens, people themselves were also to blame: I remember how amazed the rental agency guy was that I actually read the Rental Agreement and even demanded corrections before I signed anything - "Nobody reads these", he said - when even at the massive daily rate I was paid back then for my work it was still worth it to spend the 1 or 2 hours reading a contract were I was assuming a commiment of at least £15k (at the time a "reasonable" London rent for a year).

Me in your position would've just said "fuck this", cancelled SKY and gone without (and I have done it for some things were I felt the other side had abused my trust, such as closing my account with my first bank in the UK the one and only time I was charged an overdraft fee), mainly because my early adult years happenned mostly in The Netherlands so I have their style of demanding consumer rather than the more passive and willing to overlook these things style common it the UK.