§1 Liberal use of move means dynamic exciting cinematic battles.
§1b Not moving around means static boring battles.
§2 Move needs to be free to be used liberally.
§3 The only way for movement to stay free is if there is zero ways to "cash it in" for something more minmaxed (like even a single extra point of damage, or healing, or attack or defense).
I would say
1) Location / placement in combat should have advantages and disadvantages which encourage you to use movement.
2) Movement should not be free as doing leads to no true choices, if you are at a disadvantage you would be foolish to not move, if you are at an advantage you would be foolish to move.
Having a cost to movement does two things
1) Forces you to weigh the cost vs the gain in advantage
2) Allows you to consider if you could force this cost on to your opponent.
In 5e with attacks of opportunity and free movement, once a player is near the average monster, the only movement I see players do is to orbit them. Mainly so they avoid an attack of opportunity, and to hopefully get a flanking bonus (which is an optional rule!).
Stepping into combat hitting and moving back is almost never done, because you have a potential to be hit on the way back and since movement towards the creature is free it looses nothing when it approaches you.
However if you take a look at PF2. A normal creature has no attack of opportunity this allows for more movement.
PC's fighting creatures have exhibited the following strategies.
The traditional move to get into flank
The use of a move to get out of flank is more common (due to lack of op attacks)
If the one side outnumbers the other, if the outnumbered members will often step away from the horde after attacking. Because it will force the greater number of creatures to waste actions on movement that could have been used for attacks. For instance if a PC was being swarmed by lets say 3 creatures, one action step action by the PC, removing 3 actions from the monsters side.
If an opponent has a shield and the attacker does not. Stepping away after attacking a shield user will force the shield user must decide between a second attack and using the shield.