Bolted stays & dropouts vs welded/one piece

[Veloo]

What are the advantages and/or disadvantages to rear dropouts being bolted to the stays vs a one piece/ welded?

I do have a couple bikes myself with bolts seat stays. No failures so far but have wondered if the bolted ones provide less contact surface area.

I guess you can run a belt drive with them but that's a small % of the market.

[prototoast]

These are most commonly used with metal dropouts and carbon fiber seat stays as in your picture there. The bolts allows for adjustability between the angle of the seat stay and the chain stay. It also helps with fabrication because once the carbon fiber is bonded to the metal, you cannot weld the metal without destroying the carbon fiber.