Career GPG is always a poor measure imo. Goalscorers should be judged on primes and Draisaitl took longer to reach his goal scoring prime, as he didn’t become an elite goalscorer until 18-19. Since then he’s put up 307 in 499, which is a 50 goal pace per 82, and will have 6 top 5 goal finishes by the end of this year.
McDavid in that same time period has 268 in 479 or a 46 goal pace, and while he does have that dominant 64 goal Richard season, he only has one other top 5 scoring finish, a 2nd in the Covid shortened season. He does have a couple 6ths though. Even if we take last season out of the equation and add 17-18, so McDavid has his best 7 goal scoring years like Dreisaitl, that would put him at 277 in 485 or a 47 goal pace.
Draisaitl has a slightly higher goals per game in their prime goal scoring years, has more goals in 5 of the last 7 years (and 6 of their 10 years together), and better league wide goal finishes. McDavid has the best peak season, and it’s close enough that I wouldn’t make a cutoff of the top 5 like this, but I’d put Draisaitl slightly ahead as a goal scorer right now.