I use my standard glass XDR with my 2019 16" MacBook Pro. It's a 2.4 i9, 64gb ram with RP 5600M 8GB. I also have a Blackmagic Pro Vega 56 eGPU. Thinking of retiring the eGPU though as the 5600m is fairly comparable, and the dGPU lets the XDR use DSC for full speed USB ports. Right now, the eGPU doesn't have the display plugged in as it also doesn't provide enough wattage to fully power my 16" and the XDR does. I am beyond happy with the Pro Display XDR and 16" combo. It's honestly the best display I've ever used. Ultimate unobtainium. I came from the 5k Ultrafine. I'm a video editor for a small agency and occasionally need to do color grading for clients. So the accuracy of this panel is a big plus. I also feel the size is large enough (quite perfect really) that I was able to sell my Ultrafine and retire my old 27" LED Cinema Display to the kids. No more dual display needed, and my desk is much happier. If I really need to reference a script and have the editor open, I just open the display of the MacBook Pro.
I've wanted the XDR since it was released but also had a hard time coughing up the dough. I saw a pretty killer deal at MicroCenter earlier this year and just went with it. Subsequently I caught a good deal on the Pro Stand on eBay and just recently sprang for the magnetic Logi webcam for remote working.
Ultimately, if you're trying to justify it, that's unique to each person. I think everyones justification is different. For me, I've always been a fan of Apple's industrial design and I just like to enjoy my setup that I sit in front of for sometimes 10 hours a day. I've been using Apple displays since the 30" Cinema Display G5 days. The Ultrafine 5k was a great panel, but felt cheap in comparison. Remembering back to 2004, the launch price of 30" Apple Cinema Display ($3,299 USD) adjusted for inflation is about the price of the XDR today ($4,625.88), that helped me at least, as I paid less. $4,499.99 at MicroCenter.