How are you defining lesser teams more often? My research has indicated that in the O6 era, the players on our top 100 list played many more games against teams with a negative goal differential than they did teams with a positive goal differential. Take for example the 60-61 season, here's the standings:
Montreal 92 Points, +66 GD
Toronto 90 Points, +58 GD
Chicago 75 Points, +18 GD
Detroit 66 Points, -20 GD
New York 54 Points, -44 GD
Boston 43 Points, -78 GD
By definition, every team plays 14 games, 20% of the schedule against every other team. If a player was on Montreal, that means they'd play 28 games against positive goal differential teams, and 42 games against negative goal differential teams. There was also much less year to year movement in team points - between 60-61 and 66-67 Boston never broke 50 points, and their yearly goal differentials went -78, -129, -83, -42, -87, -101, -71. That's basically -1.2 goals per game. That's the equivalent of a team going -100 for 7 straight years in the modern NHL - and -100 in post-lockout era has been done exactly three times (Buffalo and Arizona in 14-15, Colorado in 16-17). A lucky player might get 10 games against those teams in those years, of the 162 total, maybe? In contrast, a player who was in the league from 60-67 got to play 98 games against Boston.
Take for example Bobby Hull - I have him as a 1.06 PPG player in 674 games prior to expansion. I have him playing 43.6% of his games against +GD teams, and obviously 56.4% of his games against -GD teams. He was a 0.94 PPG player against +GD teams, and a 1.15 PPG player against -GD teams. In the same sort of sample size, from 05-06 through 15-16, Sidney Crosby played 707 games as a 1.32 PPG player. I have him playing 52.2% of his games against +GD teams, and 47.8% against -GD teams, and he was a 1.25 PPG player against +GD teams and a 1.40 PPG player against -GD teams. (Also fwiw, in those 700 games for Chicago that Hull had an opportunity to play in, they averaged 3.01 Goals for per game, and in the 868 games that Crosby had an opportunity to play, Pittsburgh averaged 3.02 Goals for per game, so there isn't really any scoring gap between the teams.)