The ISS may not, but Starliner does have a fixed life. It is meant to fly on the Atlas V, which is end-of-life. Once those are gone Starliner would need to be

The ISS may not, but Starliner does have a fixed life. It is meant to fly on the Atlas V, which is end-of-life. Once those are gone Starliner would need to be integrated and recertified to fly on a new rocket, probably Vulcan, but it's doubtful Boeing would want to spend the money to do this. In response to your other point, I am very skeptical of microgravity experiments becoming a big industry. I think NASA (as an organization, I'm not talking about individuals in NASA) is mostly interested in continuing human space flight simply because it keeps the public interested in space, which makes NASA's funding more secure.