The only real limitations on good ones- AI, etc. is that people don’t shoot enough for quick change barrels mattering for replacement, and that on all of the common ones you have to rezero, so switching cartridges isn’t a big draw. From a reliability standpoint AI’s is certainly there. But, people (hunters) don’t shoot enough for it to matter. Also, you have a very real belief that sending a rifle to a smith is “custom”. For just replacing shot out barrels, the standard prefits done on a tailgate is just fine.
If we ever got an American version of the Sauer 404, Blaser R8, or Sako 100 where scope and barrel stayed together and absolute return to zero was assured- I would be all over it.