Summarizing reasons for not introducing this requirement:

• it's not necessary since metric attributes are already namespaced (by the metric they are on)
• longer attribute names make writing backend metric queries more cumbersome

Summarizing reasons for introducing this requirement:

• establishes that there is a single set of attributes that can be used across traces, metrics and logs
  • encourages correlation between signals, which is one of OTel's core missions
• metrics can be derived from logs
• raw measurements can be emitted via logs

I will update these summaries based on any comments made below.