The monk had actually spent character resources to be able to do the wire-fu thing. Very cool. Very in character. Rule of cool and all that.
Jumping now qualifies for the rule of cool? Well... whatever. He spent resources on the ability to jump whenever, wherever and however he wanted. He lost nothing by making the jump.
Then the paladin says, "hold my beer" and teleports to the top of the roof, no checks, no chance of failure, no drama and about as interesting as soda crackers. I mean, do you really picture, in your head, when thinking about paladins, Portapaladins bouncing around the scene? I know in our group, we had a fighter and a paladin, and the pally almost always got into a fight before the fighter. Bonus action teleport, poof, he's in the thick of things. Gee, the fighter can burn his Action Surge for extra movement, but, he's only got that once per short rest. That 8th level paladin has what, 3?, second level spells.
First up - yes, I can picture in my mind a holy warrior disintegrating into a thousand shards of light and flashing towards his foe in a flaring blast of righteous fury. Just because you lack imagination, or are willfully not exercising it because you have some sort of grudge doesn't make it any less exciting than some guy jumping a bit.
Secondly if your group is only ever having 3 fights a day, then obviously people on a resources-per-day scheme will be worse off. That's on your DM.
2. On your second point about running out of resources, well, there's a couple of things there. Firstly, the casters get SO MANY resources. Sure, Teleport might be a bit of a bit resource wise, but, the lower level stuff? Not so much. And, secondly, it starts the whole 15 MAD cycle off with a bang. The party is all (or mostly all) casters. It's in all their interests to stop for long rests and get spells back. IME, it's not unusual for 3/4 of the party to be long rest based, which means that 3/4 of the party wants to stop at the same time.
And it's up to the DM to have a world where taking the rest of the day off because you're a little tie-tie is a drawback.
First up: If they're of a level where making the
entire party fly is a trivial cost, and you aren't planning for that, then guess what, you done screwed up your dungeon design!
Ok, so they fly across and somehow the resource expenditure is trivial. What now?
Well - either they're fighting a god of death on a tiny platform and are unable to get out of melee range, OR they're flying above the mist with a diminished combat capability (the fly spell requires concentration, which is a combat resource PLUS a risk, wildshaping has obvious drawbacks, riding anything to fly has risks) and no way to take cover.
To me, those both sound like bad options unless my DM's idea of a challenging encounter is a melee bruiser who deliberately attacks the most durable party member every round. In your scenario I'd just be solving the cultist's ritual so that I've got more tactical options for the upcoming encounter.
In practice, I've never seen a session go badly because the players sidestepped a challenge via flight or teleportation. Never. Not even once.
I sort of have. The game was darksun, and we were playing the adventures that followed the prism pentad. My character was a half-giant psion with high enough stats that he could reliably use a discipline called 'wormhole' (I think?). It allowed me to instantly teleport the entire party anywhere. In retrospect, I would not have done so had I known exactly how thoroughly the modules depended on the party facing complications during overland travel, or being corralled in various city-states and having to work to escape. Towards the end of the campaign, my DM pointed out that we were several levels below the recommendations for the modules we were playing, since we'd totally skipped one entire module with two wormholes.
That said... the session still didn't go badly, because the DM just winged it.