Would you like to count the number of spaces that various items in your manifests are indented and then pass that as an argument to a structure-unaware text file templating engine? Would you like to discover your inevitable yaml file templating errors after submitting those manifests to the cluster? Then yes, you are really missing out!
I really, really, wish we could move away from yaml for tools like this.
A couple of years ago I was using https://kapitan.dev/ which I found really good at the time when using jsonnet files to generate the configs. I haven't used it for some time though.