6 to 8 actually. So 0.75-1 casting per encounter. And that's not accounting for encounters within a minute of each other.
And it only consumes your spell slots, so you can still blast away with Eldritch Blast for baseline damage.
Exactly.My take is that advantage/disadvantage, outside of spells/actions/abilities that are specifically used to provide such, should be rare. True Strike, Aid Another, Reckless Attack all have a price. Someone has to spend an action, or the barbarian grants advantage to opponents.
You seem to be under some misconception that just because you have a good cantrip there is no cost. It's been shown that there is cost, it's not debatable. I have never said it was a bad tactic, just that there is a heavy cost in anything that grants reliable advantage or disadvantage.
There are the cost of buying and caring for your mount(s), the restriction of potentially not being able to fit well in some areas while on your mount, and the disadvantage (common usage of the word, not game term) of making yourself a more prominent target for your enemies.Explain Mounted Combat then.
But I'm getting the impression that you don't want players "seeking" advantage at all; only allowing it as you said, for very specific, preset conditions (features, abilities...

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.