I think one of the boses that lately ahs reminded me of how difficult bosses used to be is
Sephiroth from Kingdom hearts, you need ti have a nice level,you need to know how he attacks and defends, you need ability with your controller... and you need a little luck also
Thats what boss battles used to be.
Other special bosses from final fantasies are EASY, you just need to know how to beat them like omega weapon, ozma, emerald weapon.... Sephioroth no matter how well you know his strategy you will still need ability (Sin harvest is devastating power)