dependencies are borked; will matter when deprecation kicks in

[felzix]

One of your dependencies, babel-preset-react-app, is importing the
"@babel/plugin-proposal-private-property-in-object" package without
declaring it in its dependencies. This is currently working because
"@babel/plugin-proposal-private-property-in-object" is already in your
node_modules folder for unrelated reasons, but it may break at any time.

babel-preset-react-app is part of the create-react-app project, which
is not maintianed anymore. It is thus unlikely that this bug will
ever be fixed. Add "@babel/plugin-proposal-private-property-in-object" to
your devDependencies to work around this error. This will make this message
go away.

[SeizureSaladd]

literally got this exact same thing in the console lol

[harsh183]

I've been facing this issue too in my project (classtranscribe/FrontEnd#819). CRA has included a fix in a commit around a year ago: 0f5e990, but there's been no release since then.

Looks like @babel/plugin-proposal-private-property-in-object is deprecated and to be replaced with @babel/plugin-transform-private-property-in-object. Babel's website babel-plugin-transform-private-property-in-object docs says

This plugin is included in @babel/preset-env, in ES2022

Here's the link to the package.json for babel-preset-react-app in CRA that's declares the dependency too.