I know what you mean; that has been a problem in the past. In case you have to again, I'd recommend looking into either Roadrunner or Swoole. That makes it possible to have your application run more or less standalone in a single container, hosted by a native application server. This boosts performance incredibly, and exposes a single HTTP port, as it should be.

For Symfony: https://github.com/k911/swoole-bundle

For Laravel: https://laravel.com/docs/8.x/octane

> The fact that I needed multiple processes (nginx+fpm)

I believe you can have fpm listen on TCP and run nginx in another container if you want, although I haven't tried it so I can't vouch for it.