Regarding the balance of physical exertion vs awareness of the natural world around you: with the exception of seriously gruelling climbs, surely nothing stops you from climbing a mountain or otherwise going on a tougher hike at the same slower pace that you describe enjoying?

Well actually your body does, as we begin to enter into a cardio workout state our brain releases drugs making us feel good and encouraging us to exercise more and push harder. The entire time someone is hiking/running there brain is saying in their head "go go go go go go". This is a very obvious aspect of 99.99% of hikers to me? Why do you think most hiking groups have so much trouble waiting up for slower people? It is because we always eventually succumb to that headspace of pushing harder and getting higher, even if the pace of someone slower is justtttt a bit slower than us we will walk at the speed our body demands even if it creates social conflicts.

https://www.rutgers.edu/news/researchers-find-runners-improve-performance-narrowing-visual-focus

A simple way for runners who want to enhance their performance is to focus on the finish line rather than taking in their surroundings, a recent study has found

A team of psychology researchers at Rutgers University-New Brunswick, New York University and Creighton University, who investigated nearly 1,600 runners, call it “narrowing one’s visual attention.”

In an investigation of nearly 1,600 runners, scientists found that narrowing visual attention – zooming in on the finish line rather than taking in the surroundings – serves as a powerful self-regulation strategy that can boost both effort and performance.

When your body is working hard your awareness plummets, this is just an aspect of being a human being. You can balance it while hiking, but almost no one does because it is mentally exhausting to keep holding your feet back from tackling the exhausting challenge you know is ahead... and even if you do you simply will never be able to be anywhere as aware of the nature around you than if you had taken a slow walk instead.

if someone cannot go to a place without vandalising it then they probably should not go, but that doesn’t invalidate the power of a personal experience

Well yes I agree but given the obsession of car culture in most places in the world, this is actually MUCH harder to do than people assume. The mass migration of everyone using personal ICE vehicles to "connect with the outdoors" is, when seen holistically, a process of strangling natural spaces not honoring them.

With all due respect, there is. You’re not advocating for walks around industrial estates or by the side of a busy road or just doing laps of your own home. You’re right that there’s a great deal of good to see in places that are less obviously notable, and also that many people miss out on that good by failing to consider it, but I don’t think we do anyone any favours by pretending that there’s no such thing as a more interesting landscape

Yes I am, explore the landscape you are surrounded by absolutely.