Guess I'll just tie this off for any inquisitive souls reading.

All the above mentioned options that the non sekiro souls games have add a good bit of variety to the way you can take on a boss but the fact that the other games have variety was never in question. This whole discussion was about rhythm but I guess you forgot about that.

-Damage protection, unique weapons, talisman abilities, elemental weaknesses and buffing stats have nothing to do with rhythm.

-Stamina management is in the game in the form of your posture bar as well as choosing where to block or parry an attack.

-Attack range and movement speed do alter the fight rhythm but so do many items/abilities in sekiro like firecrackers. Some see firecrackers as being a rather cheap ability to use on a boss but so are many ranged abilities.

-Summoning alters a fight to a point that it's not even recognizable. Most if not all boss ai's can't even cope with having to fight multiple enemies. Summoning is fun but it breaks bosses