Op, I have been there. The only thing that I can say is that sometimes, women like us are prepared to prove our independence, paid our share, show them we won’t be a burden as a previous ex and with that... we teach them not to provide for us.
A lot can be said about equality but the sticking point is that you would help him if he were in your shoes but he doesn’t. Can you change him before your own marriage gets eroded? Probably not, he is used not to provide for you.
There is also another important thing to consider, whether we like it or not, when either of the partner stops working, there is immediately a shift in power in the relationship. Simply put, they assume they are doing “more” and you put up with lousy behaviour because you “can’t” afford to leave.
I know you complain about the exw not working, but at this time you are exactly in the same place. If she has not worked for a long time, she may not get a job even if she tries very hard, the longer you are out of work, the more difficult it is to find someone willing to take the risk of employing you, so don’t put yourself in the same position.
With regards to his finances... The difference is that he is not giving the money to his ex, he is paying the carer of his kids, he is not paying for a roof over her head, but one over the heads of his own kids. IME, big levels of financial commitment after a failed marriage mostly come regularly if you have a child together. Otherwise it is just like being flatmates with benefits.