Indeed; endgame tablebases have been constructed for all positions with up to 7 pieces (including kings), and at some point in the not too distant future, we expect to have all 8 piece ones as well.
3 pieces is two kings and one other piece. That’s easy (I think it can be summed up as “draw if that piece is a knight or a bishop, won otherwise, unless the piece can be taken in move 1 or the starting position is a stalemate”)
“By 2005, all chess positions with up to six pieces (including the two kings) had been solved. By August 2012, tablebases had solved chess for every position with up to seven pieces (the positions with a lone king versus a king and five pieces were omitted because they were considered to be "rather obvious")”
With three pieces there’s about 250000 positions, can’t a modern computer just check them all?