Why Use Belly of the Beast?
Belly of the Beast is an excellent choice for Path of exile currency many builds, especially those with minions or offensive offering skills like Flesh Offering, due to the following reasons:

Huge Life Bonus: The +60 to maximum Life is a massive increase, making it great for survivability in tougher content. If you’re building for minion survivability, the extra life ensures you don’t get overwhelmed by enemy damage.

Energy Shield: The chest provides +6 to maximum Energy Shield, which is helpful if you are also focusing on Energy Shield as a defense layer. It’s great for hybrid builds or builds that use both Life and Energy Shield for defense.

Elemental Resistances: The +30% to all Elemental Resistances is a strong bonus, allowing you to more easily meet the high elemental resistance requirements for endgame content (such as T16 maps or Boss fights). Combined with other sources of resistance, this can help you stay resilient to Fire, Cold, and Lightning damage.

Scaling Life & Resistances for Minions: Since minions are often built to tank damage on your behalf, Belly of the Beast can be extremely effective in builds where you need the extra tankiness, especially if your minions are taking hits for you. The Life boost ensures your minions aren't as fragile while benefiting from POE currency for sale their own Flesh Offering or other buffs.