It’s not about it.
For example on a game i played. spiral knights. There was a boss that was totally immune to damage. To do damage on him, you had to lure him close to a bell in the center of the field, and hit the bell to stun it temporally.
The boss i most liked in the game (i not only in the game but of all time) was two giant robots, one at each side of the screen, they throwed misseles straight into another, but there was some walls you could control hitting a lever. You needed to make one of them hit the other to stun it so you could cause damage, controling the walls to allow the misseles to pass.
Search on youtube for “Snarbolax” and “Roarmulus Twin” to see those bosses.
The point is that they are more than just “run around the boss and attack”.And even that they have a pattern, each pattern is different, so you’re not just repeating the same process over and over.
For example, those pillar/traps the boss summons could have some real impact on the boss. The boss could have a huge damage reduction that would require you to break the pillars to reduce it. Or pillars that powerd the boss (to a ubrearable point) and required you to deal with them to be able to stand the boss.
Another example was from another MMO i played: the boss randomly gains a colored barrier with an effect (damage reflection, damage reduction, huge life regen), you needed to step on a magic circle (randomly distributed on the map) of the same color as the boss barrier to gain a buff that allowed you do destroy the barrier when you attack the boss.
Or even boss with two or more stages: once he loses a certain ammount of life, he changes the pattern of the attacks and become stronger.
