That's a bit like asking if a pair of shoes can be too small. Depends on the size of the feet you are putting in inside them.
You can't get simpler than than "Happy Birthday to you". You can't get simpler than the only verse of "Auld Lang Syne" that people remember and sing.
Small is beautiful, less is more, simple is best. If you can manage to say what you are trying to say, that's what matters.
"I wander as I wander out under the sky
how Jesus our saviour did come for to die
for poor sick and weary, for you and for I,
I wonder as I wander out under the sky."