I need to know this. Can Cyber Phoenix be destroyed by Smashing Ground?

Smashing Ground, Fissure, Hammer Shot etc. do not target and CAN destroy Cyber Phoenix or a Machine-Type monster while Cyber Phoenix is on the field.

Examples of targeting Magic and Trap Cards...

Any Equipment Card (for face-up monsters on the field anyways)
Tribute to the Doomed
Dark Core
Karma Cut
Change of Heart
Brain Control
Enemy Controller
Order to Smash
Spiritual Wind Art - Miyabi
Spellbinding Circle
Shadow Spell
Nightmare Wheel
Block Attack
Stop Defense
Dark Coffin
Compulsory Evacuation Device
etc


Examples of non-targeting Magic and Trap Cards....

Raigeki
Dark Hole
Fissure
Smashing Ground
Hammer Shot
Creature Swap
Divine Wrath
Swords of Revealing Light
Swords of Concealing Light
Threatening Roar
Waboku
Hallowed Life Barrier
Pole Position
Final Destiny
Bottomless Shifting Sand
Needle Ceiling
etc
etc

Somehow, the ruling involving Fissure and Smash kinda sucks as it seems that the effects designate monsters but claiming they are not.

You could probably get confused by the fact that they look for something "specific" in this case the monster with the lowest defense or lowest attack.

Well, technically, they do not "designate" anything since nothing is actually being "selected" by anything...in the case of Hammer Shot or Smashing Ground, they're like heat-seeking missiles...they automatically go after the most intense heat source (highest ATK or DEF) and if something else suddenly appears that has a higher heat source, it will automatically shift its sights onto that without anyone having any choice in the matter except to generate something with an even higher heat source.