As long as your site only works for English and is only intended to work for English this is fine. If it needs to work for other languages too, even common ones

As long as your site only works for English and is only intended to work for English this is fine. If it needs to work for other languages too, even common ones, then this isn't fine. Getting plurals to work correctly for multiple languages is hard so an alternative (that often works well) is to have locale specific strings with holes in them.