It was, to an extent, and a more authoritative leader on that particular issue would have played better, too. It was also Johnson putting in spending plans, meaning Labour went mental with their's in return - a bit like when Tories went uber-righty when Blair claimed some of their ground.
So that lost a lot of their authority. The 2017 one, sure, among certain people was seen as spend spend spend, but it played reasonably well, and was reasonably balanced too, once the party had been able to filter what Corbyn may have wanted, through what was maybe realistic. If we accept that you move a bit more centre from 2017, there's still space for basic policy goals that can remain indeterminate, and be promised when the time is right - that's surely a better approach than dismissing them entirely for the period of a parliament.
Especially when, on the other side, the former Chancellor of the Exchequer is doing a fine job of rubbishing Truss's fiscal capabilities, and is making the case for higher tax to fund higher investment!