Imo the 3090 is like the 2080ti or Titans i.e. for people with too much money who absolutely need to have the biggest, baddest and latest consumer level card.
Professionals just get a Mac Pro with a Quadro and put that on their company expense account.
The 3090 and 2080ti both have full speed NVLink which allows for resource pooling between two cards for extremely large 3D scenes and CAD files (that support the technology). Perfect for students, hobbyists, freelancers (me), and small studios. Quadros are extraordinarily expensive and offer no performance benefits in 3D rendering and outside of some CAD software (Catia for starters), they offer no performance benefits in the viewport. Just stability, validated drivers, longevity, and sometime more VRAM at the top-end. Software like Maya, 3DS Max, Blender, C4D, Houdini, etc do not run faster with Quadros. Just a little bit more stably and with fewer visual glitches (and 10BIT colour support).
This is coming from someone whose laptop has a Quadro P4200 and a Firepro w9100 and 3 Geforce cards in their desktop running Maya, Redshift, Zbrush, Blender, and Substance Painter. The one thing that is a major bugbear is that W10 is a colossal P.O.S. when it comes to 3D modeling and animation. It is soooooo slow and clunky compared to W7 on the exact same system. That is why I keep trying (and failing) to switch over to Linux/CentOS.
MacOS has dropped support for Nvidia with their last few O.S. versions and Nvidia dropped driver support for the older O.S. last year. You cannot use anything newer than Pascal with High Sierra stably, as I have heard from fellow 3D artists, Turing is incredibly buggy and most often does not work at all. I think, think the one that came after High Sierra also works with Nvidia cards but not well.
That means no CUDA support for the software that uses it exclusively. GPU rendering software which is becoming increasingly important in 3D rendering, whether it be full GPU rendering like in Redshift3D (my rendering software) or hybrid GPU/CPU software like Pixar's Renderman; Almost none support Metal, and with Redshift support still in Alpha testing, they kneecapped an entire professional segment that is growing fast.
TL;DR These top-end Geforce cards are great for small-time 3D artists and studios for their massive VRAM banks, NVLink support, and performance relative to what the more expensive Quadros offer and Nvidia does not play nice with Macs.