I have the benefit of having an 2021 A6 Allroad and a new 2025 Pure, so I cannot directly compare to the sedan A6.
My impression is that the Allroad is more refined car than the A6 sedan. (I read somewhere that the Lucid higher ups are Audi wagon aficionados and I can see that lineage in the Pure.)
First, I would suggest trying out the Allroad, which in my opinion is an outstanding ICE auto. The versatility it provides without SUV bloat is incredible. We were thinking of trading it in, but there is no car on the market that can easily go from national forest access roads to grand tourer so well (and look so good at it ;-).
The Pure certainly cannot do that.
However, the Pure is at least six times as efficient and doesn't have a German V6 gulping premium gas. It's certainly not as versatile, but I would certainly choose it over the A6 sedan.
Over the past two months I have been quite impressed at how a "version 1.0" Lucid Air has performed as well as Audi's flagship Avant model that has been refined over decades.