I would agree that Jeremy Corbyn is in many of his attributes similar to a grassroots activist. However, in 2015, when he was elected leader that was precisely what the Labour party and the whole Labour movement required, as anything else would have consigned it to oblivion.
Corbyn returned the Labour party to its grassroots activists and in that United once again the Broader affiliate membership in the country into one Labour movement.
Gone are the days when a small number in the executive made all the policy decisions which in the Blair era gave us the beginnings of Zero Hours Contracts, the Gig Economy, the Banking Crisis and the Iraq War.
However, many in the Parliamentary Labour Party have never accepted the wider democracy that the Corbyn leadership has brought about. They instead undermine Corbyn and those changes at every opportunity by way of some Blairite MPs even covertly recording private conversations with Jeremy Corbyn hoping he will make some off guard remark that they can then release to Britain's right-wing press.
In the above, those people seem not to realise that many in the broader Labour movement and many within the Labour parties own Constituency and District parties are now thoroughly disgusted with the above referred to wrecking actions of those Blairite MPs. In that a break with the present parliamentary Labour Party by the broader movement could well be on the cards in the not too distant future should the situation in the parliamentary party not change
In the above, much could well depend on the outcome of the trade union litigation against a number of high profile companies that use Gig Employment in their trading activities. After winning any number stages in the lower courts, those cases are now in the hands of the Supreme Court for final adjudication.
Only Jeremy Corbyn and a few supporting Labour MPs have brought Parliament's attention to the above action while others have "sat on their hands" and remained silent on the matter. However, should the Supreme Court rule in favour of the trades unions that may well lead many of their activists to conclude that they can survive better without continually "dragging along" a Parliamentary Labour Party that continually refuses to support many of their ambitions.
The resignation of Jeremy Corbyn as leader due to age and the winning of the Gig Economy case in the Supreme Court may well trigger changes in the Labour Movement the likes of which have not been seen for well over one hundred years.
And that I would support.
or 
!!