Having lived in various countries in Europe including over a decade in the UK, my theory is three fold:

• It already started with a system were power is dynastic (not just because of the monarchy and an unelected 2nd chamber were many members inherit their position but also because it has a well-entrenched system of private schools which tie to elite universites and from there to political, media, corporate and judiciary to positions) were there used to be some level of noblesse oblige (the duty of the upper classes toward “their lessers”) which is now completelly gone: the UK copied the “everybody for themselves” spirit from the US (but not the “go getter spirit”) into a system which was already incredibly stratified into classes and riddled with priviledge, so it basically ended up just being used by the rich scions of the rich to tell themselves their wealth is due to personal merit and from which it “logically” follows that the poverty of the poor is due to them being lazy and the rest of of the population should just do as they’re told by such clearly superior people.
• Starting in the Thatcher years the Press in the UK was bough by a handfull of very rich people who don’t pay tax in the UK, most noteably Murdoch. That fully privatised and Press whose ownership was then heavilly concentrated, was then used for propagand purposes, pushing anything and everything to make the power of the state subservient to the power of money, mainly by removal of regulation and lowering of effective corporate taxes and taxes for the wealthy (though the UK already had unique legal frameworks to allow the very wealthy to avoid all tax, most noteably the Non-Resident Tax Status) as well as views such as the above mentioned one that poverty is caused by laziness and being wealthy comes from merit.
• Being a de facto Two Party System due to a First Past The Post representative allocation system that makes it extremelly hard for a third option to rise to power (and on the rare occasions when they get close - about once every half a century - they’re quickly “put back in their place”), the extreme right in the UK, rather than try and gain power through the popular vote (as you see, for example in The Netherlands, where they float around the 15% mark) were they would require millions of votes to get power, have instead just infiltrated one of the power duopoly parties and thus only needed about 50k votes to take power (by outvoting other factions inside that party to elect their people as leaders). Once they dominated the Tory party, the First Past The Post system makes it extremelly hard to dislodge the party even though it has massivelly changed, and you even get effects like the other mainstream party of the Party Duopoly shifting its policies more towards the agenda that’s being set by the far right now in power.