It's a parliamentary party focussed on winning elections with no power to eradicate Tory policies or roll them back. You're asking for the impossible.
More properly you should be asking what the Labour Movement are doing for local constituents. That's what Momentum do: organise food banks, hold police authorities to account for their relations with BAME communities, picket where they can for such things as drawing attention to hospital closures, anti-fracking campaigns etc etc. Regardless of Momentum that's always been part of the LP tradition through organisations like trades unions and the co-operatve movement.
I suggest you look up the definition and purpose of the official opposition. I've no doubt that local groups do an awful lot, just as Frank Field did plenty locally, but the job of the opposition is to oppose, and influence policy via that opposition. It's not to sit back and watch Rome burn because they know they're the next batsman in.
The Liberal Democrats exist, and are at 6% in the polls - their entire campaign right now is as the "stop Brexit" party and have ultimately failed to win widespread popular support.
As for the price caps on energy firms, I agree that it doesn't go far enough. Energy poverty is of huge concern for many people (especially OAPs who often have to make the choice between eating or heating), and having half-arsed caps doesn't go far enough, but for the Conservatives to even admit that the current system is failing is a huge step forward from what we have seen post-Foot.
That's switching topics though isn't it? I'm well aware of how poor the LibDems have been doing, but I asked you what Labour have done on Brexit as the opposition in the house, and whether you're happy with what they've done? The Lib Dems have a handful of MPs, so are sadly rather irrelevant.