haveanicedavid I understand how this may appear appealing. Have in mind that none of the browsers you mentioned follow Apple's HIG and thus are not native apps on macOS (they appear to be out of place or even gimmicky to the "trained" eye).
We could discuss all day long whether one design is better than another, but the whole point of HIG was to prevent such discussions and have apps follow standards set by Apple, whose designers still do have the greatest authority in design (in the world probably, but certainly inside the Apple eco-system).
Thus Orion is commited to following HIG as this is not only what Apple asks of any developer but ensures consistant experience for all users. When we deviate from Apple (rarely, but happens), it is for strong reasons and convictions - for example Safari shows redundant tabs in its sidebar which we believe is against HIG and we can defend the position; second example is how Safari does compact tabs - in both we are talking more about UX choices than design though).
In this case it would be hard to defend thie position as this is literally a matter of taste question, inside very well defined design rules for macOS apps.
However the whole purpose of this forum is to have covnersations like this, and see if our users can achieve concensus. If that happens, we are more than happy to oblige. So thank you for starting the conversation and I am happy for @alicerunsonfedora to offer an opposing view.