Depends on what it is you need to repair.
If it's the OLED screen, I've found that going back to Samsung is probably the best case, also because they replace the battery too. That's what I did for my old S9+.
The cost of most 3rd party places for a screen replacement is pretty similar to what Samsung is asking for as the cost of the OLED display is very high and the removing of the screen is not easy. When you factor in the battery and the restoration of the IP68 water/dust - proofing, Samsung service centre still does it best.