Scoring isn’t everything however I don’t get what your argument is about Howe being better. Women lie, men lie- numbers don’t. And the numbers are right in front of you.
Here are some reasons why the scoring environment was so different for Howe and Lemieux:
For most of Howe's career, the season was only 70 games long. It was extended to 76 games (still less than the length during Lemieux's career) in 1969, when Howe was 40 years old. He scored 100 points right away, despite being more than a decade past his peak. Schedule length matters.
Howe peaked during one of the lowest scoring eras in NHL history. During the six years he won the Art Ross, there were just 5.26 goals per game. That's a lower scoring environment than the mid 2010's, or even the Dead Puck Era (1997 to 2004). During the six years Lemieux won the Art Ross, there were 6.87 goals per game. We still need to do a deeper dive, but this alone shows that Lemieux played in a league with 31% more goals per game. That's huge.
On top of there being fewer goals per game, there were fewer assists per goal. In 1953 (Howe's best season), there were 1.50 assists per goal leaguewide. In 1989 (Lemieux's best season), there were 1.66 assists per goal. Not a huge difference, but it still should be considered.
In 1953 (Howe's best season), he scored 49 goals and 46 assists in 70 games, in a league that featured just 4.80 goals per game. If we "translate" that into the scoring environment in 1989, we'd get 49 * 82/70 * 7.48/4.80 = 87 goals and 46 * 82/70 * 7.48/4.80 * 1.66/1.50 = 91 assists for 177 points. This is a ballpark calculation - and Lemieux is still ahead - but it's much closer than the raw numbers suggest.
Even this approach is imperfect, because there were so many fewer powerplays during Howe's best years. This disproportionately affects star players like him. In 1953, Howe led the league with 27 PP points. That would have ranked him tied for
60th in 1989 (behind players like Scott Young, Eddie Olczyk, Mike Ridley, and Walt Poddubny). The difference in PP opportunities was vast, but even before we account for that, Howe's 95 points from 1953 is worth something like 170-180 in 1989.
For the PPG calculations - not only do you need to account for all the factors I just mentioned, you're also comparing players who's career arcs are very different. Lemieux was able to preserve his PPG because he played so few games after age 31 (we see the same thing with Bobby Orr, Mike Bossy, Peter Forsberg, etc). Lemieux played just 170 games after age 31 (19% of his career total). Howe played 851 games after that age (48% of his total). That's almost Lemieux's entire career! Of course his PPG average is going to be dragged down. (Jagr is a good, similar example - when he left the NHL after 2008, his PPG was 1.26 - higher than Crosby! He came back and played several hundred games in his late 30's and into his 40's, and his PPG dropped - now it's lower than players he was very clearly better than, such as Hawerchuk, Perreault, Lafontaine, Savard, Federko, Bure, Sakic, Yzerman - in effect, Jagr is being penalized for being a healthy, productive player into his 40's - the same thing is happening to Howe in this simplistic comparison).
Plus, as others have mentioned, Howe was a physical force (ie Ovechkin or Messier) and a very good defensive forward. The plus/minus component data (goals for and goals against at ES) only exists from 1960 onwards, when Howe was already in his 30's. Even though we don't have the actual data for his peak, Howe's results from his 30's are still better than Lemieux's (in terms of how much he was able to drive his team's goal differential higher, while on the ice - which is entirely consistent with what we'd expect from both players - two-way power forward vs someone solely focused on offense).
This was a longer response than I intended. But I'm trying to show how vastly different the scoring environment was for Howe and Lemieux. Essentially all of the factors that we need to account for, have inflated Lemieux's numbers. Ultimately, I still think that Lemieux was the better offensive talent, but the gap is
vastly smaller than the numbers suggest. Peak vs peak, given Howe's two-way play and ability to stay in the lineup, I would give him a narrow edge over Lemieux. In terms of career value, it's not even close.