not in a mono-white it doesn't, i play a light dragon rush with sanctuary as protection and to me upgrading gives no advantage what so ever, even just upping the healing by a single point would be way more helpful
Going from 4 to 3 means it can come out a turn earlier most times. This is especially evident in the upped metagame where getting 3 towers is easier than 4, and it can shut down devourers, discord, and BH, things not too uncommon in PvP.
as to why its not broken i cant explain it here but if you try playing with the card for a while u'll see what i mean, its quanta cost is well thought out and altho its fragile to PC thats equaled out by the huge advantage it against a fair few deck styles
I've probably been playing Elements for longer than you have, so I don't think your comment really works here. Making it heal 5 would make it better than SoG, a pretty good rare card that requires a mark dedication.
Also, please work a little harder on your spelling, it's a bit annoying having to read typos and acronyms unless you are an eagle or have only two fingers.