diff --git a/CHANGELOG.md b/CHANGELOG.md
index 708568b2416..137b9eb8bef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - *(help)* Make `DeriveDisplayOrder` the default and removed the setting.  To sort help, set `next_display_order(None)` (#2808)
 - *(help)* Subcommand display order respects `Command::next_display_order` instead of `DeriveDisplayOrder` and using its own initial display order value (#2808)
 - *(env)* Parse `--help` and `--version` like any `ArgAction::SetTrue` flag (#3776)
+- *(derive)* Changed the default for arguments from `parse` to `value_parser`., removing `parse` support
 - *(derive)* `subcommand_required(true).arg_required_else_help(true)` is set instead of `SubcommandRequiredElseHelp` (#3280)
 
 ### Features
diff --git a/src/builder/command.rs b/src/builder/command.rs
index 549cd4e4213..7f14c716b48 100644
--- a/src/builder/command.rs
+++ b/src/builder/command.rs
@@ -482,7 +482,7 @@ impl<'help> Command<'help> {
     /// }
     /// ```
     pub fn debug_assert(mut self) {
-        self._build_all();
+        self.build();
     }
 
     /// Custom error message for post-parsing validation
@@ -3732,33 +3732,6 @@ impl<'help> Command<'help> {
         Ok(matcher.into_inner())
     }
 
-    #[doc(hidden)]
-    #[cfg_attr(
-        feature = "deprecated",
-        deprecated(since = "3.1.10", note = "Replaced with `Command::build`")
-    )]
-    pub fn _build_all(&mut self) {
-        self.build();
-    }
-
-    #[doc(hidden)]
-    #[cfg_attr(
-        feature = "deprecated",
-        deprecated(since = "3.1.10", note = "Replaced with `Command::build`")
-    )]
-    pub fn _build(&mut self) {
-        self._build_self()
-    }
-
-    #[doc(hidden)]
-    #[cfg_attr(
-        feature = "deprecated",
-        deprecated(since = "3.1.13", note = "Replaced with `Command::build`")
-    )]
-    pub fn _build_bin_names(&mut self) {
-        self._build_bin_names_internal();
-    }
-
     /// Prepare for introspecting on all included [`Command`]s
     ///
     /// Call this on the top-level [`Command`] when done building and before reading state for
diff --git a/src/builder/possible_value.rs b/src/builder/possible_value.rs
index 9c55ff1daa1..06bc2b4128d 100644
--- a/src/builder/possible_value.rs
+++ b/src/builder/possible_value.rs
@@ -172,22 +172,6 @@ impl<'help> PossibleValue<'help> {
         !self.hide && self.help.is_some()
     }
 
-    /// Get the name if argument value is not hidden, `None` otherwise
-    #[cfg_attr(
-        feature = "deprecated",
-        deprecated(
-            since = "3.1.4",
-            note = "Use `PossibleValue::is_hide_set` and `PossibleValue::get_name`"
-        )
-    )]
-    pub fn get_visible_name(&self) -> Option<&'help str> {
-        if self.hide {
-            None
-        } else {
-            Some(self.name)
-        }
-    }
-
     /// Get the name if argument value is not hidden, `None` otherwise,
     /// but wrapped in quotes if it contains whitespace
     pub(crate) fn get_visible_quoted_name(&self) -> Option<Cow<'help, str>> {
diff --git a/src/parser/matches/arg_matches.rs b/src/parser/matches/arg_matches.rs
index a60bf7d8459..d7c473d11d9 100644
--- a/src/parser/matches/arg_matches.rs
+++ b/src/parser/matches/arg_matches.rs
@@ -672,24 +672,6 @@ impl ArgMatches {
         };
         Some(i)
     }
-
-    #[inline]
-    #[doc(hidden)]
-    #[cfg_attr(
-        feature = "deprecated",
-        deprecated(since = "3.2.0", note = "Replaced with `ArgMatches::try_get_one()`")
-    )]
-    pub fn is_valid_arg(&self, _id: impl Key) -> bool {
-        #[cfg(debug_assertions)]
-        {
-            let id = Id::from(_id);
-            id == Id::empty_hash() || self.valid_args.contains(&id)
-        }
-        #[cfg(not(debug_assertions))]
-        {
-            true
-        }
-    }
 }
 
 /// # Subcommands