Like you say, there's loads of ammunition, but a restricted bandwidth to get any message across to the public, and even then it's subject to being distorted or clouded.
Don't underestimate how readily some duffers now convince themselves that something's fake news, it's truly shocking.
The point you raise here is probably the most significant difficulty that Labour face, although I do think that that is now changing.
In the past the T.V. or print were the only medium available for the political parties to convey their respective messages and since the overwhelming majority of newspapers are/were owned by Tory party donors or supporters it's not surprising that the Conservative party enjoyed far more positive exposure whilst at the same time framing Labour in as negative light as possible.
Since the advent of the internet though, it does appear that Social Media has been the great leveller and that ALL parties now have a level playing field regarding the internet. Sadly, nothing has changed regarding newspapers. The problem is that now Labour have a level playing field regarding media, they are missing some HUGE open goals. I fully agree with posts made earlier that Labour M.P.'s should be calling out the CONservatives at every opportunity, God knows there is enough ammunition out there to sink a battleship, but they either say nothing or give some long winded wishy washy answer a la Barry Gardiner. I cringe when I see this guy on the telly.
It is no good trying to be the nice guy in a cut-throat business, the sharks will eat you alive and I think the same problem haunts us as a football club.