dtgreene: I can think of a few counter-examples, in which, past a certain point, leveling up becomes easier as you progress.
Too bad I play JRPGs much less.
I think the general idea is that you also gain more XP from later subquests and you face harder enemies that give you more XP, but still very few RPGs seem to get the balance right that it feels like your progression isn't severely slowed down later in the game. Or is that the whole point, you are supposed to level up much more rarely later on?
And no I do not want an Oblivion system either where _all_ enemies level up with you (hence giving you more XP), it just feels fake. In a way I like Gothic's approach where you are free to go fight orcs or hellhounds already in the beginning... only to find out that you can't even damage them at all, while they kill you with one hit. So, you learn to avoid them until you can beat them in some way.
The problem with Gothic is that I have apparently killed almost all the monsters at least out in the wilderness already, and they respawn very slowly (I think only one enemy per a bunch respawns when you progress to a new chapter; meaning that if you e.g. killed a pack of five wolves in chapter 3, then in chapter 4 one of them comes back). So now when I run around trying to find something to kill, at best I run into one singular monster at a time which gives me a bit of extra XP and is a total pushover as it is alone.
In a way I like that respawn system too because if they kept respawning too fast and too often, it would be too easy to just stay in one spot killing the same enemies over and over again. And that is exactly what I could apparently do late in the game in the Sleeper's temple, by "summoning" a demon and killing it over and over again (600 XP per kill), but even that felt far too slow progression at this point, and too tedious to pull out.
As said, apparently I just decided to try my wings also with magic too late in the game. The game apparently expects you to decide much earlier whether you will be primarily a magic user or a fighter type. If you try to have it all, then you pretty much run out of XP.
I got a similar feeling in Fallout Tactics. There were so many perks that I still wanted to get, but levelling up became so uncommon later in the game that e.g. running around for random encounters became too tedious.