Don't feel bad for them. Stop judging them while believing otherwise. Mind your own business and stop meddling. Consider that you might be engaging in ableism. Be their friend (if they are also friends to you) and enjoy your life with them when the opportunities present themselves. Don't see anything you do as "enabling them" - it's not your job to give them tough love or to intervene in any way, unless they are asking you specifically for help. In that case, it's reasonable to set conditions or limits to the help you may choose to give them.

Not everybody is worried about achieving things in life or living in ways you approve of, their regret isn't guaranteed, and there are always ways for them to start anew and to live with dignity e.g. like the people showcased on the CheapRVLiving YT channel.

Society isn't healthy, so it may be wise to direct your energy towards improving it and encouraging others to do the same. Their level of integration into our incredibly unhealthy society is not a measure of their personal health.