Keir Starmer is the sort of Labour politician I used to be wary of (not only a lawyer, but a human rights lawyer), but given he is just about the only candidate for the leader's job who has any sort of real-life success, I don't see who else can be effective as party leader.
The alternatives: Lady Nugee, Titania McGrath lookalike Rebecca Wrong-Daily, 30-something grandmother Angela Rayner, thick-as-two-short planks Burgon; are truly horrifying.
I think Labour are going to have to accept that they are pretty much done for the time being in the Midlands outside the big cities (Mansfield is staying blue now), and in many of the northern seats they lost (and trends may see them lose in places like Hartlepool and Sunderland given time).
There has been a big realignment in politics, and a majority of ordinary small-town and suburban/Ex-urban whites see Labour as having nothing to offer them at best (if they are not viewed as actively hostile to their interests).
Labour remain the party for urban areas with high numbers of ethnic minorities (London/Leicester/Brum/Manchester/Bradford/Blackburn), very-high-levels of deprivation and cultural aversion to voting Conservative (South Wales Valleys, Merseyside, Tyneside), and areas with lots of academics and well-paid public sector workers (which are often the posh bits (West Wirral, Tynemouth etc.) of places already mentioned). Rapid demographic change is going to hand them wins over the Tories almost by default in the working-class suburbs of outer-London (and perhaps in some provincial cities). It is here, in bohemian semi-rural places (Stroud, High Peak), and anywhere with a University or teaching hospital that is not already red that offer the chance for revival.
A prominent role for Jess Phillips (another Labourite of the sort I'd be wary off*, middle-class with nepotistic connections, loudmouth, lazy-feminist opinions) might keep on board the significant minority of ordinary folk who have stayed loyal to Labour, and help win back some of the more surprising losses.
*Although I much prefer her to the similar middle-class with connections Luciana Berger