I'm not disagreeing with you, but you should invert the question and think about it.
In the case of a cathedral, I think it is relatively easy to commit to the project you won't see through, it has a significance to those people making the commitment. What becomes much more challenging is when future generations don't have the same level of commitment, it's a much bigger ask to stop. Maybe there is a better use of the resources that could impact people immediately; if it's a church, I'm thinking feeding the hungry and clothing the naked sorts of things. It's hard to stop something that "we've just been doing." It's also hard to ask "why are we doing this?"
In 200 years, suppose there is some crisis we cannot predict and the recital is to be interrupted or stopped. There will be an incredible amount of pressure on somebody to make a good choice. Pressure that was created by a distant ancestor, of sorts. That might be part of the beauty of it, that might be part of the bond that ties different people together throughout time and it might be wonderful. What if there is a caretaker that is ready to retire and cannot find the next caretaker? That seems like a horrible position to be in.
Japan is or was doing multi-generational mortgages a while back (I assume they might still be.) as it was the only way a family could afford to buy a property. I can see that being a tremendously loving act for your children or grandchildren in providing a property that they will own, but I could just as well see it being a gigantic burden to them, what if they want to live somewhere else? Them following their bliss effectively changes the living and working future of the parents.