Yup. And the differences are also strategic.
I think campaigning for Corbynite Labour is a waste of energy. A Corbyn-led government, if it ever happens, might be marginally better than May (the hyperbole that calls him Marxist is so far wide of the mark as to be ludicrous), but because you can’t have socialism in one country (because capitalism is global, so opposition has to be global), he wouldn’t get away with anything the international capitalist institutions and so on couldn’t swallow. (David Harvey in a recent podcast gives the example of Mitterand having to reverse hard on various manifesto commitments once in power). This is called “the realities” and realpolitik.
So while I might (might) cast a vote for a political party for some tactical reason, going further than that: campaigning for one, joining one, is a diversion. Even when they have good intentions, they get coopted and subsumed in the establishment. Look at the history of the Labour Party. (And if you think Atlee is a shining beacon, remember the welfare state and the NHS were mooted before he took power by others in the establishment, were supported by Tory governments and the post War Consensus after he left power, and were in fact a compromise that capital felt it had to concede to - small l - labour in the wake of the War. It was a necessary pressure value, in the view of capital. It came from years of working class activity and pressure, not because of one GE result. That result was an effect not a cause).
Reduction of politics into electoral politics is misdirection and saps useful energy.
So, while you can’t have “socialism in one country”, the working class can, if organised, cohesive and strong, win useful concessions at historic points of crisis. The energy therefore needs to go into working class organisation and activity.