Guildford
Conservative Bloc 2015: 65.9
Conservative Bloc 2019: 44.9
Swing: 21.0
Esher and Walton
Conservative Bloc 2015: 72.6
Conservative Bloc 2019: 49.4
Swing: 23.2
Wokingham
Conservative Bloc 2015: 67.6
Conservative Bloc 2019: 49.6
Swing: 18.0
Sevenoaks
Conservative Bloc 2015: 74.8
Conservative Bloc 2019: 60.7
Swing: 14.1
Tunbridge Wells
Conservative Bloc 2015: 71.3
Conservative Bloc 2019: 55.1
Swing: 16.2
Runnymede and Weybridge
Conservative Bloc 2015: 73.6
Conservative Bloc 2019: 55.8
Swing: 17.8
South West Hertfordshire
Conservative Bloc 2015: 68.4
Conservative Bloc 2019: 49.6
Swing: 18.8
Surrey Heath
Conservative Bloc 2015: 74.2
Conservative Bloc 2019: 59.7
Swing: 14.5
Reigate
Conservative Bloc 2015: 70.1
Conservative Bloc 2019: 55.1
Swing: 15.0
Chesham and Amersham
Conservative Bloc 2015: 72.8
Conservative Bloc 2019: 55.4
Swing: 17.4
St Albans
Conservative Bloc 2015: 54.4
Conservative Bloc 2019: 39.2
Swing: 15.2
You really think there's nothing here?
With all due respect you really don't understand British politics at all do you?
A large chunk of the Lib Dem vote especially in posh suburban places like these would prefer the Tories to Labour given the choice (indeed many were Tory voters until the Brexit saga) especially as it seems unlikely that Labour will return to the centre with the next leader likely being Rebecca Long-Bailey. It was Tory fear-mongering about the Lib Dems putting Labour in that stopped many Tory Remainers in places like Esher from voting Lib Dem which cost them a large number of seats. If the Lib Dems were stupid enough to openly associate themselves with Labour the Tory Remainers that they did manage to win over would go scurrying back to their former party leaving the Lib Dems with nothing except a decent second or two in Streatham or Hornsey.
Similarly a large chunk of Labour's base regard the Lib Dems as little better than the Tories (indeed many Labour activists actually regard them as worse as at least the Tories 'fight fair' apparently) hence the whole '#YellowTories' thing on Twitter. Labour is also very tribal and I believe that it's written into the party's constitution that they're obligated to contest every seat (except those in Northern Ireland which its sister party the SDLP contests as well as the Speaker's seat).
As for the comparison with Canada that I see @DistingFlyer made with the North being Tory and the Home Counties all Labour/Lib Dem: this scenario would only work if the Lib Dems displaced Labour as the main opposition to the Tories which is not going to happen as Labour has a far too loyal base and hence a decent floor. If Canada was like the UK and if instead of rebounding under Trudeau the Liberals had gone into to terminal decline dropping to ~10 seats in 2015 the Tories would dominate the 905 whilst the NDP would hold sway in Northern Ontario.
Labour's path back to government lies through getting back at least the greater part of the seats they just lost, especially the more urban ones like the West Bromwich seats, though some of the more rural ones e.g. Bishop Auckland may indeed be gone. Couple this with expanding into poorer areas in the South such as Cornwall as well as diversifying middle-of-the-road commuter towns like Milton Keynes or High Wycombe and Labour could build a sustainaable coalition with Brexit sorted.
As for the Lib Dems, where I do agree with you is that there is a huge opportunity for the Lib Dems in posh commuterville (where I live) but it is not by allying themselves to Labour, if anything they should be distancing themselves further. If this is the route they want to go down they should re-brand as the 'sensible, pragmatic' party with a solemn duty for putting the breaks on the 'extremism' of the Conservatives and Labour; whilst at the same time pushing the 'party of business' narrative (especially responsible business) and tie this into an internationalist world view. They should be very pro-environment/sustainability though leaving the more extreme sounding anti-growth stuff to the Greens. On social issues be liberal and pro-freedom (obviously) though they should avoid getting dragged into the latest 'woke' obsession e.g. announcing pronouns or self I.D which raises more than a few eyebrows round these parts. This is basically how they'd take the Home Counties from the Tories and establish a very solid base here, though I somewhat doubt they'll go down this route.
Also please don't add Labour and the Lib Dems vote shares together and draw conclusions from it (similarly for the Tory and Brexit Party votes) as the two are not interchangeable. It's as silly as adding the Tory vote to the Labour vote and inferring that huge number means that the vast majority of Britain is illiberal.