On the one hand, this is reasonable - focus on appealing to the centre. It is clear that Labour needs to win the next election.
On the other hand, such strategy has led to a 'ratchet effect' of denuded public provision. We see the Tories in office (Thatcher, Austerity, Truss) aggressively take the country rightwards, attacking trade unions, reducing access to employment tribunals, shrinking or diverting into private pockets the money that is spent on public services, privatising, academising, centralising power. Then Labour come in. They make small steps leftward, but they don't undo any privatisations, and they don't undo the marketisation of public services, in fact they like some of this stuff - they introduce student loans, PFI, and 'light touch regulation' of the banks. And at the end of their term, things are better than when the Tories left power. That will do for now; but the underlying position is still further right than before the Tories were last in power.
And then the Tories get back in, and do radical stuff (Universal Credit, Austerity, Hard Brexit, Royal Mail etc). Labour get in and timidly dial back a few policies (they can't afford more, because the tax base has been squeezed). We end up still further right. The 'ratchet effect' continues. And the voting system ensures that the Labour Party have less time in power than the Tories.
At some point, Labour has to realise that even voters in the centre want some left-wing policies: people want publicly owned rail and utilities; people want an NHS that is not market-driven and stuffed with managers. Labour will not lose votes if they promise these things. Look at
Philip Oppenheim's letter to the FT this week (
Twitter), calling for a raft of reforms. Wherever left-wing policies are popular, Labour needs to be bold, or it loses even when it wins.