I also strongly agree with favoring on map/visible encounters over random encounters. For me, I believe that if the player was constantly subdued into a random battle during the entirety of the game while he/she was, for example, exploring the scenery, on a timed sidequest, was low on health and had to get to a merchant, a speedrunner (a gamer who attempts to finish a game in the fastest amount of time), or trying to farm for EXP, it would be highly aggravating, tedious and annoying if the player was cut off from performing previous activities to fight in a battle they did not request nor want.
In some RPG Fantasy games, I find it highly irritating to be, for example, in a forest gathering key items for a sidequest or performing an action of my own accord, and then suddenly, yanked into a random battle without consent and and forced to fight for little to none EXP or rewards, then suddenly, after escaping the battle, I would find myself in disorientation for a split-second wondering what I was doing to begin with and then remembering, and then knowing that the exact same cycle would happen all over again.
I would prefer visible monster encounters because it gives the player a preemptive of what is to come and offers a player a choice of if he/she prefers to do battle with this foe. Also, the player, for example, may want to do battle with a specific foe, probably to complete the requirements of a sidequest or farm this monster for EXP, and with random battles, this is moderately difficult to achieve, but with visible battles it can be very easy.
Also, if the creator was to constantly have trouble creating events for monsters and placing said monster events over and over again, they could create all the visible monster events and place them all in an unused map. That way, when they wanted to implement a visible monster herein, it can all be done in a simple click with copy and paste into the used map, and there you have it.
This is why I favor the on map/visible monster encounters over the random battle encounters.
- Tornado Summoner