Mob fight balancing

In minecraft mobs arent as balanced as it should be in my oppinion. When leveling up gear, items enchantments most players lose either enjoyment or challenge mobs used to give when theres was no armour and just sword alone starting new world. 

CHANGE

Now i propose a bit different mechanic. When player armour increases mobs have a small chance to spawn with different negative effects (that affect player for 0,5-1,5 seconds). We all know it, we have wither skeletons, stay and more hostile mobs which do give negative effects. But regardless its one of the many ways it can be changed.

DIFFERENT WAY TO BALANCE MOBS

Zombie horse rider was a great major change to mob behaviour and balancing fights a bit. Still even in early game its too easy to kill. Other proposition would be to increase chance around player for mobs to spawn with armour or stronger enchants (according to player armour). 

HARDCORE MODE 

While this change could pose a more exciting enviroment for survival mode, it would be overwhelming to Hardcore players. So why not play Hardcore for Survival mode players  or change difficulty? The point is its not matter of difficulty, but proposition to keep challenge and enjoyment trought the game while not making it litterally hell of a place. SO it would be great to add more various combinations of mobs or just varying mechanics, because some players wouldnt want to lose game or just die friequently.

I hope others think so too.