The Forum has discussed this matter several times to my knowledge - so do a search and look up the old threads.
The two systems are different and were devised for differing uses of the horse - neither is easier than the other at a basic level. The horses are trained differently, the tack is different, the seating position is different and the system of aids is different.
If you really are keen to know the answer to your question then go find a Western riding club and try for yourself. It will be good experience for you.
But don't ask an English trained horse to do a sliding stop
Nor a Western trained horse to go round a show jumping course
- that is until you have had one for a few months and taught them how to do it.
If you seek a simplistic explanation then the answer might be
An English trained rider wears a hard hat and sits on a English saddle holding the reins in two hands and jumps fences
A Western trained rider wears a cowboy hat, sits on a saddle with a horn and holds the reins in one hand and chases cows
But that simplistic answer isn't really the answer to your question.