Hello. In Vietnamese does not important about article. So the simplicity or simplicity are corecct. :D
In English it sounds better without 'the', but I've been marked wrong so many times for omitting an unnecessary 'the' that I fell into the same trap and included 'the' here, and was marked wrong. Quite frustrating, really.
Somewhat different depending on context but similar enough to be accepted, IMHO. Do you ask for acceptance? BTW, I omitted the "to" and that was accepted.
I was marked incorrect for "The simplicity helps me succeed." Should this be correct?