It's also incredibly irrelevant, Google is not the ones being investigated here, and Stadia has also been shut down so it's not relevant at all how much better or worse it is.
The question is not which platform is better or worse, but if Microsoft could potentially abuse their position if the merger goes through.
I recommend you to either read the final report (https://assets.publishing.service.gov.uk/media/644939aa529ed...) or the summary of the final report (https://assets.publishing.service.gov.uk/media/6448f377814c6...). Probably the summary is a bit easier to digest, as it's 20 pages rather than 418 pages, but it has all the information you need to understand the case, as most news sources don't go into much depth.