[policy, no patch] When should service arguments be wrapped?

Problem/Motivation

Currently, all core service definitions put their arguments on one long line:

arguments: ['@something', '@something.else', '@another_one', '@getting_long', '@cheaper', '@by.the.dozen']

In reviewing #3041885: Display relevant Security Advisories data for Drupal → , @larowlan pointed out that sometimes, with services that have many dependencies, these lines are harder to read, and might be better if we used the list format:

arguments:
  - '@something'
  - '@something.else'
  - '@another_one'
  - '@getting_long'
  - '@cheaper'
  - '@by.the.dozen'

At his suggestion, I'm opening this issue to decide when, if ever, service arguments should span multiple lines, instead of one long line.

Steps to reproduce

N/A

Proposed resolution

Decide if the standard should be changed, and if so, how.

Remaining tasks

Talk about it until this issue reaches approximately 7,000 comments and generates its own gravitational field, then change policy. Or not. :)

User interface changes

None.

API changes

None.

Data model changes

None.

Release notes snippet

None.