Make monsters can only spawn in completely darkness (lightlevel <= 0) thus surface will be much more peaceful
If you have problems with Optifine in old versions, check out JustAnotherSpawner ( http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1288431-just-another-spawner-jas-v0-14 )
PM me if you got any problems.
Source codes can be found at: https://github.com/zlainsama/PeacefulSurface
Explain for configuration on wiki: https://github.com/zlainsama/PeacefulSurface/wiki
DefaultRule: https://github.com/zlainsama/PeacefulSurface/wiki/DefaultRule.json
You can edit rules and also have multiple rules further customizing your game.
Future fabric versions are updated in this separate project.