Most of my RPG time are spent on DS so I cannot speak for other consoles.
Anyhow, I think that RPG nowaday lacks difficulty.
This is not about the boss battles, but simply enemies encounters.
I'd like to see larger monsters group.
I'd like to see them spawn with different monsters that enhance each other.
I'd like to see them spawn with weaker monsters but are somewhat dangerous little helpers if you fail to get rid of them.
A recent example for DQ9. Golem spawning with caster monsters.
Golem would take you 2 to 3 turns to kill it off with all your team hitting it.
Meanwhile, the casters would be killed off easily in 1 turn before they throw deadly AoE spells on your group.
However, the Golem would jump in and block any attacks you try to land on the casters. One of those naturally ability that allows the Golem to protect any ally low on HP.
Now, i've encounter such groups but they are no more than group of 4 total. Making it not much a risk rather than an annoyance.
I'd like to see these common battles to randomize more and have larger groups that the players could test their tatics or run away.
The last game that I remember using the run away option at all was Strange Journey but that wasn't because it was hard, it was cheap oh-KO spells and that's not a cool in my book.
DQ9, IMO, lack the large battles. They comes in group of 4 max most of the time.