That is not necessarily true in a lot of cases. There have been a number of indie developers that have touted the Switch version of their game either being the best selling or comparable to other releases. Beyond that games in the Lego series, Rayman Legends, Sonic Forces, L.A Noire have sold on par with (at least with Xbox) or in some cases more than their PS4/XOne counterparts.
This is slightly off topic, but I am surprised you own a Switch. I would have thought you would be the last person on the planet to purchase one. I am curious as to what game tipped you over into purchasing one?
I agree that indies have found their home on Switch, but differentiate them from regular 3rd parties since the pricing is different. LA Noire definitely didn't sell on par with PS or Xbox since you need to take into account the sales of the original PS360 game. I agree with the other examples you mentioned, that's why I said "generally".
I bought the Switch for Fire Emblem Warriors and it exceeded my expectations. It was my 2017 GOTY in the action genre. Also bought Xenoblade 2 but stopped playing after a few chapters. Will probably resume at some point.