There is always a trade off between extending life and function and allowing a person to do what gives them most comfort. If your respiratory problems are progressive and incurable you need to make a personal decision based on your needs and feelings. When I was nursing I would often support a patients request to
smoke once they had reached a point where recovery was impossible despite the requirement to promote healthy behaviours. If you still have life to live and feel able to do the things you want then the trade off of vapes for O ² therapy is probably the right one but it should be your decision.