Both blade and rubber have their contribution to the end result.
Since I am very familiar with the MX-K and FX-S or similar rubbers, when I get another blade and use those, I can very quickly learn what the blade is about.
On the flip side, if I use my main blade and slap on some rubbers, I can quickly learn what the rubbers are about and if I can use it effectively enough to suit me.
It took me a while, but I learned that on FH, I do best with a medium spong at ahrdest and maybe play better with a softer sponged modern dynamic rubber. On BH I discover I can use just about any inverted rubber, but am just a tiny bit better with softer modern dynamic rubbers or even softer old-school rubber, like say Nittaku Hammond or Moristo.
For a blade, when I need to develop more touch and shot construction, a slower ALL+ or OFF- blade that spins easy is the thing for me. When I am in tourney mode, most of the year I use an easy spinning OFF wood or composite blade with feel.
It is important for a player to discover what category works for them if they have matured enough as a player. While building skill, it is important to play with the equipment that makes it easier to do most of the shots needed, so that will vary, but many are developing attackers and can benefit from a couple categories.