What happens when your game evens out and low level zones are empty?
What happens when hunting log isn't enough to grant my alt classes levels?

I'll tell you what happens... running around as a level 7 Lancer struggling to gain experience because nobody is doing Fates and the Fates don't scale properly for me to solo them.

I'm on a very populated server (Behemoth) and as of right now, Central Shroud and Western LaNoscea are both empty with roughly 6-7 people in them, and nobody is doing fates.

I'm asking you, how do I level? my hunting log alone isn't enough and since I've done every quest on my 50 and nobody is doing fates, what can I do?

you want my suggestion?

1. Scale Fates, if nobody is around I should be able to solo it.
2. Reset Guild Hests and Side Quests when you switch class
3. Add more monsters to each hunting log bracket, or increase EXP gained by 100%.