The year to year margins offensively between players will never be like they were in the 80's because no teams score 400 goals a season any more but career wise no one currently in the NHL is even close to McDavid, he is elite every season and at the top of the charts every single season. Other players at their absolute best for 1 or 2 seasons match what McDavid does every season.
It wasn't "teams". It was just the Gretzky Oilers at his absolute peak.
The 10 highest scoring non-Oilers of the 80s.
Flames 88 - 397
Islanders 82 - 385
Kings 89 - 376 (Gretzky in on 44.7% of goals)
Flames 85 - 363
Nordiques 84 - 360
Canadiens 82 - 360
Jets 85 - 358
Islanders 84 - 357
Nordiques 82 - 356
Islanders 81 - 355
With the Oilers
Oilers 84 - 446 (Gretzky in on 46.0% of goals)
Oilers 86 - 426 (Gretzky in on 50.5% of goals)
Oiles 83 - 424 (Gretzky in on 46.2% of goals)
Oilers 82 - 417 (Gretzky in on 50.8% of goals)
Oilers 85 - 401 (Gretzky in on 51.9% of goals)
Oilers 87 - 372 (Gretzky in on 49.2% of goals)
Oilers 88 - 363 (Gretzky in on 41.0% of goals)
Look at this year
Avalanche - 230 GF (MacKinnon in on 45.6% of goals)
Oilers - 212 GF (McDavid in on 46.7% of goals)
Lightning - 211 GF (Kucherov in on 49.8% of goals)
Gretzky was able to put up 50+% of team goals in Cup-winning deep teams 3 times. Yes, he's not putting up 215 today. But there's no reason to think he wouldn't dominate to a greater degree than McDavid does.