McDavid is clearly the better player now, but it's not by much.
I have a feeling though, 10 years down the line, assuming that both stay healthy, this is going to be a much closer debate, and perhaps even in favour of Matthews. Auston is on the 'better team', is playing a more complete game at aged 23, is scoring more goals (which always trumps assists and points), and has a game that is going to age better in the late 20s/early 30s than McDavid's.
In short, if we're talking about peak seasons among the GOATs, I'd go with McDavid - but in terms of the long term and long haul, I'd go with Matthews. In terms of team and career success, it's also Matthews. The Leafs have their problems and skeptics, but I see the Oilers a few steps behind the Leafs.