I'm no Microsoft apologist, but I believe you've misunderstood the intention and the effect of the changes.
Previously, the time-optimal strategy to acquire iron and diamonds was to dig a hole deep into the earth and then bore straight paths. This was exceptionally grindy (fans would say zen, detractors would say tedious), but effective.
With 1.18, the optimal strategy is now to enter a cave and find the resources there. The holes in the ground that you dislike are entry points to that system, where many resources are available -- though at the risk of encounters with monsters.
So the transition is from a static grind to the new system based on cave exploration and risk. It's more dynamic and engaging, directly the opposite of your claim here. You mention iron, claiming that progress is slower, but in actuality it's significantly easier to acquire useful amounts of iron now. Jump into any random cave and it's all over the place. Sure, there's a lot of relatively useless copper too, but no one is forcing you to mine it. Just skip what you don't need and you don't need to manage it in your inventory.
Likewise, the new topology with increased heights means that rivers are significantly more important for exploring. You point out that it makes it more difficult to go from one peak to the next, which is accurate (though in my opinion you overstate the difficulty), but regardless it is quite easy to make long journeys if you follow the rivers and low terrain.
So yeah it's harder to go directly in a straight line than it was in before, but now you're paying attention to the terrain in the world and adapting your gameplay as a result. It just requires different navigation techniques. Like it or not, you're absolutely not stuck at spawn.
