Indeed, puts that moronic centrist meme of "MAY RAN THE WORST CAMPAIGN EVER!!" in perspective.
To be fair the huge popular vote results of Labour 2017 and the Tories in both 2017 and 2019 says more about the decline of the Lib Dems first and UKIP later than it says about either of them
Johnson got less seats than Thatcher 1987 despite having a higher percentage of the popular vote
Theresa May got less seats than Major 1992 despite having a higher percentage of the popular vote
And of course Corbyn 2017 got a result comparable to Blair 2001. But while Blair got more than 400 seats in 2001, Corbyn did not even get a Labour minority.
The answer to "Why Labour and the Tories do so great on the PV" is the fact that the Lib Dems used to get 25% of the vote and they now get 10%. This is especially noticeable for the Tories as Labour has lost their Scottish vote while the Tories actually went up there.
IMO a better comparison would be the PV gap between the 2 main parties. You could adjust this to just look at the 2 party vote, but even without adjustments (and rounding) you get since the 1980s:
2019: Tory+12
2017: Tory+2
2015: Tory+7
2010: Tory+7
2005: Labour+3
2001: Labour+9
1997: Labour+12
1992: Tory+8
1987: Tory+11
1983: Tory+15
So Boris Johnson got a victory on par with Blair's landslide of 1997. The only reason he does not have 400 seats is because of vote consolidation and the death of the Lib Dems. But this is certainly a testament to how good his campaign was (and conversely how utterly terrible Corbyn's was)
As for May, notice how she had the closest PV result? Given the circumstances of the election, her campaign was absolutely terrible given how she only managed to barely eke out a win