The armor texture model does not support translucency despite supporting full transparency. Does not work when using custom armor textures either. This was last supported in 1.14 and earlier for standard armor retexturing.
[media][media]
MC-276456
Armor Texture Unable to be made Translucent (Partially Opaque/Transparent)
Resolved
Duplicate
1
(Unassigned)
Unconfirmed
Textures and models
rendering, texture
1.21.1, 24w36a
Retrieved
This may be a duplicate of or related to MC-98308