Back many years ago LGA was like a small airports for regional to medium haul flights, its mostly single aisle and turboprop airliners but somehow they used to have DC-10s, L-1011, A300s, and the obviously the 767 (even the -400)
With that much planes LGA seems to be very busy as Widebodies can be suited for Laguardia since some planes can take off at Short runways perfectly into like Medium haul to Short haul flights and even on landings there also great.
However… Fast foward to today it seems to be only Narrowbodys they can go there as the CRJ, A320, 737, ERJ, & A220, Soooooo what happened to them? well its seem to be about capacity in like Widebodies like 767, or Wingspan because LGA is a small airport it seems the wingspan might be too big for LGA even its busy, Air Canada Used to operated some Rares 767s into LaGuardia but a few months ago they retired them so its no more,Even Worse Boeing 757s are also rare even its a Narrowbody, IDK about delta though, Well only for Today LaGuardia only prefers planes size in frequency.
Well some good things that some DC-10/KC-10 seems to arrive a laguardia but only for special purposes
But one day LGA might be built bigger and better maybe they will come back but who knows