I made the same point when Matthews signed, although I was including players who make exactly 10M, and it has just become worse since:
Chicago was the first team to have a 10M or greater player when in 2015/16 Toews and Kane broke that barrier.
2016 - Chicago made playoffs - lost first round (and remember this team won the cup the year before - but I guess they were over the hill the very next year).
2017 - Chicago made playoffs - swept in first round
2017 - LA did not make the playoffs
2018 - Chicago - did not make the playoffs.
2018 - LA - swept first round
2019 - LA - did not make the playoffs
2019 - Buffalo - did not make the playoffs
2019 - Edmonton - did not make the playoffs
2019 - Chicago - did not make the playoffs
2019 - Montreal - did not make the playoffs
2019 - Toronto - lost in the first round.
That brings us up to 11 teams - 7 missing the playoffs - 4 losing in the first round with a combined record of 6 wins, 16 losses.
2020 - Edmonton - 12th in the league - loses play-in round
2020 - Toronto - tied for 13th in the league - loses play-in round
2020 - Florida - 15th - loses play-in round
2020 - New York Rangers - 19th - swept in play-in round
2020 - Chicago - 23rd - beats Edmonton in play-in, loses first round
2020 - Montreal 24th - wins play-in, down 3-2 in first round
2020 - Buffalo - 25th - does not qualify for play-in
2020 - LA - 28th - does not qualify for play-in
2020 - San Jose - 29th - does not qualify for play-in
That brings it up to 20 teams over 5 seasons - with only 6 making it to the first round with a record of 9 wins, 23 losses so far. 5 losing that series, and the other one being down 3-2 so far.
It is a bad record.
(edit - did not know that Stamkos was posting something similar when I posted mine).