I am not convinced the stagnation or downward trend is either inevitable or irreversible.

The impact of the last 1–2 decades of policies and global/regional events may continue feeding through and making things worse (or at least stopping them getting much better) for some time. However, the fact that the change of government hasn’t magically fixed everything does not mean that it won’t eventually start to have a positive impact or that the direction of travel is one way. Equally, the new government is far from perfect and has made quite a few unforced errors alongside the positive changes, so success is far from guaranteed.

Of course, if people in general don’t start to believe it by the next election and we end up with a Reform government (or even more Tories given their current state), all bets are off.