Labour as a whole haven't really grasped where they stand anymore, they're in their own echo chambers and largely squabbling amongst themselves. They're exactly where the Tory party were from the mid 90s to 2010 constantly fighting amongst themselves while New Labour had virtually no opposition.
The good news is that times change but the bad news is that they are in for the long haul and are unlikely to storm back to power in time for the next election. Part of the reason there's a lack of unity in their ranks is because they think Boris will be a one term PM and a changing of the guard will be inevitable given time. There's a misguided belief that the next scandal will the be one that sinks him without accounting for the fact that he'll get a bounce when he's cleared of wrongdoing because he knows to stay just within the bounds of what is allowed (see: yesterday's ruling on the flat refurb). This very much the tactic Democrats used with Trump, particularly during Russiagate, and I don't believe it had much effect.
Starmer has been fairly mediocre opposition so far but I think the reason for this is that he genuinely understands that the PM - for all his many leadership faults - is actually an excellent politician and any attacks need to be fatal for it to move the needle. Policy does matter and, if Starmer was up against Cameron or May, then he would probably be doing better in the polls. The trouble is policy is largely ideologically driven whereas the current government are not ideologically driven - they'll happily adopt (or partially adopt) any popular policies that have sufficient traction. So what's the point of picking a battle on those grounds? Therefore the best place to be is to frame discussion around execution.
Lastly, it's not just about people arguing in Westminister. Most of the country doesn't care about that as much as we think. Labour themselves need to deliver for local communities and councils for them to convince people that they'll be more competent. But they aren't. The Tories are. Believe it or not, places like Teeside have seen substantial progress these past few years and that's why you have the likes of Ben Houchen being re-elected by a landslide.