When you say "does a decent job" the question is compared to what ? If you are genuinely satisfied with the output of your printer, That is what counts the most. If you are interested in showing the maximum possible quality available from a camera like a D850, the answer is you can do significantly better.
True large format , wide Gamut photographic printers can make really wonderful and noticeably superior prints in an optimized workflow. Which includes providing an optimized file --usually a 16bit TIFF in the appropriate color space, and density.
Many labs work mostly from JPEGs which limits your color space to sRGB. The D850 files can exceed Adobe RGB.
However it is unlikely that any file you send to a lab will be the best possible file for the way they are set up. That's why people 'soft proof' to dial in an optimized file, or have printers controlled by RIP (Raster image Processor) software like Image Print.
If you are serious about getting the best quality, pick a lab that Accepts TIFFS in at least ADOBE RGB and speak to them about making some test prints. Once you dial in your file prep and you get good tests, order the big print and then stick with that lab. (---You may be able to try soft proofing in your editing software)
The most important thing is how much effort you want to put into the process. There is no wrong answer, they are your prints and it is your money. Very nice prints can be made from JPEGS. Depending on the file, not all pictures necessarily need a wide gamut printer, others benefit a great deal.
It takes time and effort to find out.
The best place to start is by looking at great prints.
Like many things, getting to 80% of possible quality is easy, getting to 90% is much harder, above that Harder still.
Nowadays, 80% looks very good vs any historical comparison, but you will know when you see the really good ones.