Is the tutorial really unskipable

[Enomiel]

I know it's not that long, but it's really annoying to have my hand taken through the basics of a game I started playing in 1997.

[Kurt Angle's Neck]

Nope, you can skip it. From the main menu click the gear cog, then go to Account Settings and there should be an option in there to skip it.

[Gryfn]

This tells you how to skip the New Player Experience.
https://draftsim.com/mtg-arena-starter-deck-duel/