First of all, i suggest you read this link about “footsies”:
*Footsies is a term that basically describes the entire groundgame.
Secondly, what you described is basically the essence of Street Fighter(and FG’s in general though SF is extremely focused on the groundgame and spacing).
It isn’t just fluff or a cool theory, it’s real. Most decent players apply some concept of footsies to their neutral conciousely or subconsciousely. However, while all of this is true and real mindgames are happening during the neutral, this won’t work against low level players. The reason for this is, is that they themselves do not know which buttons to press at which ranges and at which timings. If the player themselves do not really know what they are doing in the neutral, pressing buttons without a true purpose but pressing them for the sake of pressing them and wanting to do damage, how will the opponent be able to play any real footsies.
Footsies isn’t just walking into your range and pressing the best button, it’s not a 1player game, the opponent will not let you do that.
In these instances the opponent would want to play a very safe style without forcing anything and simply punishing the mistakes of the low level player. The only footsies that is happening here is standing at the max range distance of their best pokes(sweep for instance) and waiting for that poke to come so you cna punish it on block or whiff punish it. reacting to them walking forward or dashing forward and stopping them with fast pokes yourself and anti airing their jumps.
At higher level play you’ll see things like this:
Karin does st.mk to keep the oponent out s soon as they walk into that range. Next time the opponent will walk into that rnage and back out, and they’ll try to whiff punish the st.mk of Karin with their appropriate normal.
This is done on anticipation btw, her st.mk is too fast t punish on reaction with a medium or heavy attack. The timing is what is important to recognize and which poke they press. The st.mk has a hitbox that seems to go over low attacks, so trying to whiff punish or counterpoke it with a low attack seems to be a bad idea. Cammy for instance can do st.mp or st.hp and buffer it into her spiral arrow for a knockdown.
Karin gets hit and is knocked down and eventually it’s back to neutral. Now cammy will wlak into the same range again and then slightly back and press her st.mp/st.hp again, however this time the Karin player didn’t bite.
Instead the Karin player was waiting for Cammy her Counterpoke and Karin walks forward around the time Cammy does her st.mp/st.hp and sweeps it.
Next situation, back to neutral, both parties have been hit by eachother, they are no dancing in and out of their ranges looking for specific pokes, they are are not coming. The cammy player recognizes Karin is looking for something to counterpoke with her cr.hk. Cammy cna now do a few things:
 Can walk forward a LOT more because karin is looking for something to counterpoke, which isn’t coming. Cammy cna get close enough to press st.mp and start her pressure from there
 Cammy can dash as Karin isn’t looking for the dash.
[*] Cammy can press a fast light attack around the same time as where she did the st.mp/st.hp. The light recovers fast enough where cammy can block the baited cr.hk of karin. cr.hk is blocked and cammy punishes.
This is all from one exchange that evolved during the match.
Now, this little dance looks like a back and forth, if you keep doing this back and forth walking at the same timings you will be extremely predictable. So you have to mix it up how you are “dancing” back and forth on the screen, after they opponent sees you walking back, theyll know you’ll walk forward after that and you’ll get clipped by an attack as you aren’t holding block. So walk back shortly then block. walk back, do a dash. Walk forward a bit, stand neutral(decreases your hurtbox, makes pokes whiff more easily), walk forward again after whiffed poke etc etc.
If the opponent is walking back and forth a lot you cna do a sweep once in a while or anothe rlong range poke. They start blockng more during neutral and you cna use it as a way to get in more easily.
Another aspect is using the approach from the air by jumping. If the opponent is very focues on the groundgame you cna sneak in a jump attack, it delays their reaction time to anti air. It’s hard to instantly make the switch to anti airing an opponent when you are focused on the groundgame. if you throw in empty jumps from further ranges anti airs can whiff, and you cna punish it on the ground, this makes the player even more hesitant.
Another aspect of footsies, though in a very specific context is doing a blockstring and intenionall pushing yourself to a certain range and allowing the opponent to press a button, which makes for an easy whiff punish opportunity. You as a player have tested the range against that character and know nothing can reach you eventhough it looks like it can, players also want to retaliate and gain their own offensive momentum or atleats want to interrupt yours. A personal thing i did was this:
[*] In USFIV with Cody i would do a certain blockstring and push muself out of ryu his cr.mk range, i bait the cr.mk while standing and punish it with either cr.lk xx special or with f.mp
All of this also explains why the corner is so dangerous, the person in the corner cannot walk in our out of their ranges while pressing a button. The corner isn’t dangerous due to character getting extended combos, it’s the fact you don’t control or have any advantage while in the corner when trying to play the groundgame. It’s also a LOT easier to space yourself against an opponent that is stuck in the corner.
I hope i brought some clarification with the stuff i wrote and if not, atleast read the link i wrote as that explains a lot of these concepts much betetr than i did.
Some players to watch forgood footsies are Daigo, Sakonoko, Justin Wong Alex Valle, Tokido, heck most top players really.