The real takeaway is that the actual organized working class in Britain is dead and died decades ago. Scotland realized southern England loves the Tories so much they'll literally destroy the Union to keep them in perpetual power, so they fled for SNP and Labour lost what constituencies they had there. That leaves some legacy constituencies in the North and maybe Wales too that despise the Tories, which really isn't enough to outnumber the rock solid Tory base.

Thatcher killed the organizational base of the party, Blair sacrificed long-tetm credibility for short-term electoral victories. So once the Blairite shot in the arm committed suicide via Iraq and the 2008 crisis, Labour is pretty much permanently a controlled opposition party going forward.