Games, games, games. Even if it's not particularly strong on the (new) Nintendo first party front, ultimately people buy the box to play the games, and the Switch is becoming a monster when it comes to ports, older titles, and indies in particular.
Also, since the console is more similar to a handheld/DS than console/Wii, it make sense that its sales trajectory is more closely following that of the former. Being part-handheld means that many will buy the console multiple times via new models and sometimes even multiple Switch consoles per household - as individuals will often want their own to play with.
"We hold these truths to be self-evident - all men and women created by the, go-you know.. you know the thing!" - Joe Biden