You movement in combat equals your speed and speed equals walking, so you are in fact walking in combat when you go 30 feet.
No, sorry, this is a very partial (and actually totally wrong) way of looking at things. It's the distance that you can indeed walk in the time of one round, IF YOU ARE WALKING, and it is further confirmed by the movement rate when you are walking to travel in chapter 8 (you can indeed walk 300 feet in one minute, which equates to 30 feet per round).
However, in combat, you are not only moving, in any given round, you are also performing an action, sometimes a bonus action, even free interaction with an object, and a few other free things like uttering a few sentences, etc.
But the easiest way to see it is that, since the dash action allows you basically to gain extra movement equal to what you get with your move action, the move action takes at most (possibly equal to, but only in some cases) HALF YOUR TIME in a round. Which means that, basically, you move at least (considering actions) at the DOUBLE of your walking speed in combat. I seem to remember that 3e called it hustling, not running, not dashing, but certainly not strolling through combat.
Moreover, as people who have been in fights will tell you, it's certainly not a continuous move like walking, it's burst of speed as well as stop and go, here and there, hither and yon, to avoid things, look at other things (and in particular look in all directions), dodge, etc. So you might be able to cover a distance that is more or less equal to your standard walking distance, but there is no way you are walking through it, there is at least a factor 2, but probably closer to 3 in a lot of cases (multiple attacks spread through your move, for example, yes some attacks can be considered running attacks, but it's not the principle of the game which assumes that you are standing in place when performing your action).
So, considering all the above, claiming that one is walking in combat is not only ludicrous in terms of description, but wrong by at least a factor TWO technically if that is what interests you.
Them's the rules, just you are arguing that I can stop a fireball in mid explosion and do my readied action when it makes no sense, you are walking in combat even though it makes no sense. At least unless you dash, then you are walking 30 feet and picking up the pace for the next 30.
Since all the above is based on "walking in combat" which is completely false as proven above, I will disregard it.
That being said, there is a great instance of someone walking through battle, from one of my favourite go-to genre books when discussing how I visualise combat especially at high level, but for me it's certainly the exception rather than the rule: "A moment later he saw Kiruna, face serenely unconcerned, striding like a queen of battles along a path carved for her by three Warders and the fires that leaped from her own hands."
So yes, if you are a Green (battle) Ajah Aes Sedai with three warders carving a path for you, I will allow you to describe your movement as "striding". But I'm pretty certain you are not, no offense intended.
