Right that's correct. It shows SKU usage but not mapped to actual instance id. And we have the scenario you are talking about - lots of same sku with variable cost and no way to correlate it without using bigquery it seems
We really should revolt against this. I should be able to have a view of all of my billing without having to pay extra. It also shouldn't be hidden behind a bigquery export, it should be easy view what is being spent and what is causing it.
It's funny this is coming up now. Just yesterday in GCP I was trying to figure out our billing and looking at what was costing such a huge amount. I couldn't figure out any way to map the actual service being used to the price on the normal reporting or even on the billing cost table export. The only way I could figure out how to do it was to enable log export. They used to have an option to download that as a file. They disabled that a while ago and now it's only available as a bigquery export. Which is exported every day. I was like "Why would that they do that ?" Oh cause now I have to set up big query and pay for all that. So I have to pay extra JUST TO SEE my detailed billing information. Pretty ridiculous.