It's not that EMT-Is are not used widely in New York, in this particular area they aren't used. If you go up north there are tons of agencies certified at the EMT-I level. I can think of one in Sullivan County that is, and sometimes BLS units up north would even get an AEMT-I as their BLS intercept. Yeah they may not be able to do nearly as much as a Paramedic but sometimes it makes a difference. For instance you have a pt who is requiring medications... If it's a bad call at least once you get the medic intercept there is already an IV Established, takes one more step away and quicker patient care.
So it really depends where you are, and what your region allows. I'm in AEMT-I Class now and we learn how to do IO, Decompress, and other skills not allowed by the local REMACs.