Do I let my older sibling become homeless?

Hey all just looking for some advice here.

I have an older brother who is in his 40s (I’m in my early 30s). He is a very lazy and unmotivated person to the point he no longer wants to work. My mom has been supporting him his whole life. She got him every job since high school to the point all he has to do is show up (since it’s at her current workplace) but now he can’t do that. Once my mom retires in a couple months surely he will be fired. He only shows up now a couple times a week when he feels like it.

My mom makes “jokes” that I’ll have to take care of him when she’s gone but truely I know she’s serious about this.

I’m sure my brother is severely depressed but we tried to get him to speak to a therapist, which he refused. He doesn’t communicate at all about his feelings or what’s going on in his mind. He rents a room for $500/month that my mom pays. He let his car registration and license expire. He lives in a different state so my mom is constantly stressed about him.

I told my mom she needs to stop enabling him but she cannot just let him figure it out for himself. She thinks he will just end up on the streets homeless. I think the guilt is slowly killing her and making her depressed.

Is anyone else in a similar position and can offer advice? Is the only option to walk away and let him figure it out (or not) on his own?