Oh I understand, it's terribly frustrating I'm sure to not see the votes materialize and fear helping the alternative in power. :/ But frankly, if you're voting Lib Dem rather than Labour in FPTP, that's also going to help the Tories, but at least you won't feel dirty if they win and do things in your name.
Any vote you don't pass to Labour will be a -1 to them (only in case you would have voted Labour if not for Corbyn).
Any vote you pass to Tories will be a +1, an extra vote they normally wouldn't have gotten. The difference between -1 and +1 is 2. So if you vote Tory, your vote kinda counts double for the Tories.
If however, you vote for Lib Dems, that's a +1 for Lib Dems, a 0 for Tories, but still a -1 for Labour. Most important is, people got an indication there are others who want to vote Lib Dem in their constituency. Next time they might vote Lib Dem too. If they don't see others voting Lib Dem, they'll be more inclined to vote tactically for the least worst option.
In the above sense, it's important to remember that 1% of people changing their vote on Brexit from Leave to Remain would be a 2% difference in the result (+1% for Remain, -1% for Leave). I think we're long past the treshold by now. So "Getting Brexit done" as the Tories say (which it won't be, it's just starting) is actually very undemocratic in that sense.
It seems a lot of people don't understand that Brexit hasn't started yet and signing the paperwork to leave isn't actually finishing up, that will signal the start of either a transition period or an abrupt end to workable relations which won't be reversed easily.
Honestly, it's probably worse.
I mean, if reasonable people were in charge to mitigate. But you probably get Lord Bad Hairday Worse Pickpocket to lay the foundations of recuperation, he won't care of taking care of the things that bother normal people without diplomatic priviliges since it won't be bothering him personally.
