Your words; "the middle class is dying in every country mentioned because of progressive taxes, and countries like England especially are self-destructed because of confiscatory taxes". SORRY, THOSE STATEMENTS ARE SIMPLY NOT TRUE. The exact opposite has happened. Progressive taxes were installed in 1920 in most western countries (in response to the 1918 Commie Bolshevik Russian Revolution) and that created a HUGE economic boom in the western world. Maxing out about 92% sometime around 1950. From 1950 to 1980 our top marginal income tax rate for our richest top 0.1% was reduced to about 72%, which would have been fine if we left it there. Since then, however, our top marginal income tax rate has dropped from 72% to 8%. The fact is, our middle class are dying because rich people are paying FAR LESS tax, and financial burdens are falling onto the Middle Class. Exactly as Thomas Piketty's research predicted in his book "Capital". Yes, people in the Middle Class are suffering, but not for the reasons you stated.
The other thing that is killing the UK is Brexit, when they knowingly and willingly walled themselves off from Europe. Dumbest thing they've done in a long time. Unfortunately, they followed direction and promises from their hard-right-wing liar political party, which has since been run out of power. But the damage was done, and now it's very difficult to reverse.