This is an entirely delusional twitter-brain take.
Despite its problems, the UK is still a sixth largest economy, a cultural powerhouse (how many Hollywood actors are British?), with a lot of soft power, a capable and currently renewed nuclear arsenal (Astraea and Dreadnought are on track), a globe-spanning network of alliances (from AUKUS to Japan deploying to the UK first time in their history to being one of the closest and most unwavering allies for Ukraine), and a constitutionally healthy and adaptive system of government (we just passed another constitutional change and it's not a big deal, we can just do that).
Frankly, this meme stinks of projection. Going from a shining city on a hill to a place where public executions by state backed paramilitaries are just another partisan talking point, that starts Special Military Operations with no plan or goal, that threatens to annex territory of its allies in about a year is an achievement. I guess projecting this free fall on the UK makes living through it more bearable.