I feel like you fundamentally don’t understand what class archetypes are. Warriors and paladins are tanks.
Tanks are basically the shield of the party. They don’t really do a lot of damage but they keep everyone else safe by making enemies target them and being good at not dying. The thing with tanks is that a lot of their complexity comes from the fact that they need to adapt their play depending on what they are fighting. Every boss fight is entirely unique and mastering exactly how to do all of them is an expression of skill and keeps the combat engaging and fresh.
Dps classes on the other hand generally tend to stand far away from enemies and do lots of damage. They have more complex tool kits because they generally don’t tend to need to adapt a whole lot beside occasionally dodging projectiles. Almost every fight they are doing the same thing standing far away and bombarding the enemies in front of them so the process of attacking should be complicated to keep it engaging.
Supports like muskets and bards buff and heal the party. They don’t do a lot of damage and they have okay survivability due to being able to heal themselves. I will admit supports are very strong and important but they are also totally reliant on their party. They fulfil a totally unique role and exist mostly in the background. Supports exist somewhere inbetween tanks and dps for flexibility. They have moderately complicated tool kits because they have to adapt their play to match different boss fights but not as much as tanks do.
In terms of your specific criticisms:
Warrior is complex late game because it lacks a diverse tool kit rather than despite it. Because you don’t have a lot of mobility or damage mitigation you actually have to fully engage with all of the bosses mechanics and you have to plan out the fight in a very precise way. For example you might have to strategically place players to sword rush to them, you have to dodge slams, and you have to constantly be calculating hits to perfectly avoid breaking your shield before every tank buster.
Paladin on the other hand is by far the most overpowered overloaded class in the game. It has infinite mobility, can keep like a 95% stunlock and kiting uptime on bosses, does way too much damage for a tank, can just ignore mechanics with its shield, passively takes 1/2 damage to allow it to just ignore slams, can heal to full instantly, and has a very low skill floor. The class is super easy to level because it does a lot of damage and doesn’t die when enemies hit it. Late game it can not only carry but entirely solo a significant portion of late game content. I personally have soloed every dungeon in highstepe as a level 1 shard and could probably go as high as a level 4 or 5. The thing with paladin is that it gets hammer pips when it takes damage so if you aren’t getting them fast enough you just need to take off your armor or fight more or harder enemies. Playing paladin late game is actually a constant struggle to get rid your pips because enemies hit you so hard and its very easy to max out and instantly die.
I will admit i do agree that shaman can feel a bit underwhelming. It’s simplistic play style does provide a lot of accessibility though so its really good for more casual players and I feel like it does the right amount of dps for its skill requirement.
