Switch well and truly hammering 3DS, should pass it easily unless Nintendo do something astoundingly dumb like dumping support prematurely.
As for DS, the fact they're even still in the same ballpark is impressive given DS's monstrous total sales. I don't expect Switch to have the same kind of insane total, but it's a good sign.
Switch is doing great. I expect we will learn soon the big Switch games for holiday 2020. AC will help boost sales up as long as shortages aren't too bad.
DS had a slow start, but picked up huge steam later on.