Yaarel
🇮🇱 🇺🇦 He-Mage
I understood, that is your view.Which is what I'm saying. A druid will not wear metal armor even if they gain proficiency in all armors from some other source.
The nonproficiency with metal armor is a big deal. Wearing nonproficient armor prevents spellcasting.
But I see it as only true for the Druid class training, per se. Special situations like a feat can modify this training to learn to cast Druid spells while wearing metal armor proficiently.