Years ago, Google use to separate the ads in its search results not just with clearer ad labels but also with a line separating the ads from the organic/free listings. Google may be testing that again, as we spotted a line separator between the ads and organic results just recently.
Khushal Bherwani spotted this in action the other day and shared a screenshot on X. Here is that screenshot:
I was unable to replicate this, I do not see line separators between the ads and organic results.
And to be honest, Google is mixing ads with organic results more often now, so why bother?
Forum discussion at X.