We are likely to be borrowing to pay for things that don't generate growth, that is primarily why we are seen as a poor bet and that is where the similarity between truss/kwarteng and Starmer/reeves begins and ends. I have long been calling for labour to shut up about Liz Truss because it lets the preceding 10 or so years off the hook.
I don't claim to be able to put all the jigsaw pieces together but in 2010 and 2015 we were continually told a) labour didn't 'fix the roof while the sun was shining' and b) the government would clear the deficit and start paying down debt. B didn't happen for a variety of reasons and basically the Tories have done exactly what they accused labour of doing in (a). Then COVID hit and the national debt ballooned out of control. If you look back over the last few years I have been saying how ****ed we are, personally (through priority bills rising, stagnant wages and ridiculous housing costs) and quite often you have been saying that's too negative. The time for radical policies was ages ago, labour are now in a position where anything they do won't fix it and they seem to just be managing the inevitable decline. The reality is the British public have been living on hot air for years.
Labour will go one of two ways, try and spend their way out of it (which possibly can work if the money goes to things that create impetus) or cut. My feeling of Reeves has always been that she will opt for the tried, tested and failed option of austerity (probably through the backdoor).