diff --git a/crates/store/re_types/definitions/rerun/components/blob.fbs b/crates/store/re_types/definitions/rerun/components/blob.fbs
index b6d6ed9ef91c..d391371b30c2 100644
--- a/crates/store/re_types/definitions/rerun/components/blob.fbs
+++ b/crates/store/re_types/definitions/rerun/components/blob.fbs
@@ -9,7 +9,7 @@ table Blob (
   "attr.arrow.transparent",
   "attr.python.aliases": "bytes, npt.NDArray[np.uint8]",
   "attr.python.array_aliases": "bytes, npt.NDArray[np.uint8]",
-  "attr.rust.derive": "Default, PartialEq, Eq",
+  "attr.rust.derive": "PartialEq, Eq",
   "attr.rust.repr": "transparent"
 ) {
   data: rerun.datatypes.Blob (order: 100);
diff --git a/crates/store/re_types/definitions/rerun/components/image_buffer.fbs b/crates/store/re_types/definitions/rerun/components/image_buffer.fbs
index 10981a26e489..db63f79a09c7 100644
--- a/crates/store/re_types/definitions/rerun/components/image_buffer.fbs
+++ b/crates/store/re_types/definitions/rerun/components/image_buffer.fbs
@@ -9,7 +9,7 @@ table ImageBuffer (
   "attr.arrow.transparent",
   "attr.python.aliases": "bytes, npt.NDArray[np.uint8]",
   "attr.python.array_aliases": "bytes, npt.NDArray[np.uint8]",
-  "attr.rust.derive": "Default, PartialEq, Eq",
+  "attr.rust.derive": "PartialEq, Eq",
   "attr.rust.repr": "transparent"
 ) {
   buffer: rerun.datatypes.Blob (order: 100);
diff --git a/crates/store/re_types/src/components/blob.rs b/crates/store/re_types/src/components/blob.rs
index 5eaa2871021b..2d5e717b8ab5 100644
--- a/crates/store/re_types/src/components/blob.rs
+++ b/crates/store/re_types/src/components/blob.rs
@@ -21,7 +21,7 @@ use ::re_types_core::{DeserializationError, DeserializationResult};
 /// **Component**: A binary blob of data.
 ///
 /// Ref-counted internally and therefore cheap to clone.
-#[derive(Clone, Debug, Default, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct Blob(pub crate::datatypes::Blob);
 
diff --git a/crates/store/re_types/src/components/image_buffer.rs b/crates/store/re_types/src/components/image_buffer.rs
index 969b2cd0825c..954a4cff5a52 100644
--- a/crates/store/re_types/src/components/image_buffer.rs
+++ b/crates/store/re_types/src/components/image_buffer.rs
@@ -21,7 +21,7 @@ use ::re_types_core::{DeserializationError, DeserializationResult};
 /// **Component**: A buffer that is known to store image data.
 ///
 /// To interpret the contents of this buffer, see, [`components::ImageFormat`][crate::components::ImageFormat].
-#[derive(Clone, Debug, Default, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[repr(transparent)]
 pub struct ImageBuffer(pub crate::datatypes::Blob);
 
diff --git a/crates/store/re_types/src/components/show_labels_ext.rs b/crates/store/re_types/src/components/show_labels_ext.rs
index 8914bba71ea0..67931c338f01 100644
--- a/crates/store/re_types/src/components/show_labels_ext.rs
+++ b/crates/store/re_types/src/components/show_labels_ext.rs
@@ -1,14 +1,5 @@
 use super::ShowLabels;
 
-impl Default for ShowLabels {
-    #[inline]
-    fn default() -> Self {
-        // We don't actually use this default -- visualizers choose a fallback value --
-        // but it is necessary to satisfy `re_viewer::reflection::generate_component_reflection()`.
-        Self(true.into())
-    }
-}
-
 impl From<ShowLabels> for bool {
     #[inline]
     fn from(value: ShowLabels) -> Self {
diff --git a/crates/store/re_types/src/datatypes/blob_ext.rs b/crates/store/re_types/src/datatypes/blob_ext.rs
index 1d48545d3622..55897c6f59b0 100644
--- a/crates/store/re_types/src/datatypes/blob_ext.rs
+++ b/crates/store/re_types/src/datatypes/blob_ext.rs
@@ -20,13 +20,6 @@ impl From<Vec<u8>> for Blob {
     }
 }
 
-impl Default for Blob {
-    #[inline]
-    fn default() -> Self {
-        Self(Vec::new().into())
-    }
-}
-
 impl std::ops::Deref for Blob {
     type Target = re_types_core::ArrowBuffer<u8>;
 
diff --git a/crates/viewer/re_viewer/src/reflection/mod.rs b/crates/viewer/re_viewer/src/reflection/mod.rs
index 106295f5b4e2..349507a027db 100644
--- a/crates/viewer/re_viewer/src/reflection/mod.rs
+++ b/crates/viewer/re_viewer/src/reflection/mod.rs
@@ -292,7 +292,7 @@ fn generate_component_reflection() -> Result<ComponentReflectionMap, Serializati
             <Blob as Loggable>::name(),
             ComponentReflection {
                 docstring_md: "A binary blob of data.",
-                custom_placeholder: Some(Blob::default().to_arrow()?),
+                custom_placeholder: None,
             },
         ),
         (
@@ -390,7 +390,7 @@ fn generate_component_reflection() -> Result<ComponentReflectionMap, Serializati
             <ImageBuffer as Loggable>::name(),
             ComponentReflection {
                 docstring_md: "A buffer that is known to store image data.\n\nTo interpret the contents of this buffer, see, [`components.ImageFormat`](https://rerun.io/docs/reference/types/components/image_format).",
-                custom_placeholder: Some(ImageBuffer::default().to_arrow()?),
+                custom_placeholder: None,
             },
         ),
         (
@@ -579,7 +579,7 @@ fn generate_component_reflection() -> Result<ComponentReflectionMap, Serializati
             <ShowLabels as Loggable>::name(),
             ComponentReflection {
                 docstring_md: "Whether the entity's [`components.Text`](https://rerun.io/docs/reference/types/components/text) label is shown.\n\nThe main purpose of this component existing separately from the labels themselves\nis to be overridden when desired, to allow hiding and showing from the viewer and\nblueprints.",
-                custom_placeholder: Some(ShowLabels::default().to_arrow()?),
+                custom_placeholder: None,
             },
         ),
         (