That and:
Communication(free)
Water walking(free)
Double jump(1Ki)
Reduce/nullify falling(free)
All of these things are (a) highly circumstantial, and (b) available as rituals / low level spells to spellcasters.
I have never seen or played in a campaign where this was relevant.
Invisibility(4 Ki)
Ability to go into different planes of existence (8 Ki)
The 18th level ability you mean? A level when spellcasters are bending the fabric of reality itself?
Darkness (2ki)
Silence (2ki)
Pass without Trace (2 ki)
Darkvision (2 Ki)
These are decent abilities, available to one subclass of monk... but by the time the monk can use them without severely hampering their combat capability, actual spellcasters have enough spell slots that if they need one of these, a 2nd level slot is not such a precious resource.
Teleportation (free)
Invisibility (free)
Also neat abilities, but the invisibility one comes on quite late, and the teleportation one would be good if the rest of the class actually had features that actually let them leverage the extra mobility.
Elemental Attunement (free)
Gaseous form (4 Ki)
Fly (4 ki)
Shape flowing River (1 Ki)
Wall of Stone (6 Ki)
Yeah, not gonna get into four-elements monk. Everything they can do is way overpriced in terms of ki, and way cuts into their ability to be functional the rest of the time.
A monk is a much better tank than a rogue since they can turn invisible and gain resistance to all damage. They also get proficiency on all saves and rerolls for 1/monk level resources with a maximum of 1/14th of their resources.
Again, 18th level is not a super-relevant point of comparison. Their saves are better than rogues' after 14th level, yes. But not by a huge margin; a rogue gets an extra feat, so can pick up CON saves, for example, and gets Wisdom saves around the same time that the monk gets diamond soul. When it comes to avoiding attack damage, the rogue is better unless the monk hampers their offense severely by dodging all the time. As for actually "tanking", as in taking heat off your allies, why would an enemy go after a creature that isn't a significant threat to them?
They have better damage than a rogue for the majority of their time before gaining much better tanking qualities.
No?
Having a high AC doesn't really contribute to the party. They mostly just help the fighter stay alive. But also their are a number of classes that get things like that.
You brought up poison and disease immunity in the context of 'utility'.
Why would a wizard ever pick up Comprehend Language? Practically a waste since the bard most assuredly already has it.
Wizards get to use rituals without preparing them. I take Comprehend Languages all the time on my wizards. It doesn't come up that often, but I take it anyway. That's at 1st level. Tongues is at 5th. The monk gets their tongue feature at 13th.