You cannot compare these. While it is true that the switch sold 13 million+ units it’s first year, these are worldwide sales, while the Steam deck started (and still is) only in a few select markets, and started at a bit over 1 million units sold the first year. That’s what, 8% compared to the Switch’s first year? The deck was not being sold (at least not directly) in over 92% of the countries where the Switch was, so it seems like they are on par, or at least very close, by region.

Also consider that the switch is more targeted at kids, while the deck is targeted at more mature players.