Currently Bower is not the recommended way of loading assets any more. And the SpBowerBundle is deprecated/abandoned. Symfony 4 supports the use of Webpack.
The following documentation is affected:
Set up a plan for the use of Webpack in Integrated
Create a list with things, files, documentation, etc. which have to be changed
A problem of the current Bower setup is that a bower package may include php files, which will be placed in the web root. If you are not aware, this can introduce a security leak. Hopefully this is better with Webpack.
A problem of the current Bower setup is that a deletion or privatization of a repository ruins a deployment. Hopefully this is better with Webpack.