I'm a LibDem member, so maybe I shouldn't write this, but I think the LibDems had a poor campaign. Part of the problem for them is that they have no money and don't have rich donors. My local branch apparently has absolutely no money left in the bank. I don't think the media is kind to Tim Farron.
The LDs relied on Brexit in a number of by-elections and local elections, which was a successful strategy, but there were problems in the South West heartlands, because those areas voted Leave. The strategy didn't work well in a general election.
The LDs failed to regain (or lost) seats in Cambridge, Leeds North West and Manchester Withington. All constituencies had previously had good LD MPs and I know something about them. The Labour Party had pro-Remain candidates, who were all honest about their position and promised to campaign for a soft Brexit. In the end, voters were more concerned about austerity and just hoped that Labour would challenge the Conservatives' position on Brexit. They also felt that a Labour MP would have more clout than a LibDem one.
PS. I think the Labour Party still has a problem with Brexit, because their new younger members don't want it, but the older, more traditional voters do (although there is some doubt about that, because some Ukip voters have returned to Labour). If I were a Labour Party strategist, the last thing I would want at the moment would be to be in government. Let the Conservatives make a hash of things and take ownership, then be around to pick up the pieces.
Ironically, the LibDems might get a second referendum/softer Brexit anyway.