Then when she develops more serious health or mental problems, and you have nobody to help look after your children, relationship therapy has burned through a couple therapists, and you're telling each other how lonely you each are but avoid real conversations because they inevitably lead to more loneliness, then you will again have a new perspective. Good luck.
I guess I am going to be the only person to defend this statement. I see where you are coming from and I’m willing to give you the benefit of a doubt that you meant the “hypothetical you”.
But to use the old cliché- it’s better to have loved and lost than to never have loved at all.
Having the childcare load shift due to a partner's health issue is something that will happen. I have been there and it isn't easy. But personally I was happy to step up and am proud of how I acted in that moment. Sorry to hear about what sounds like your more negative experience.
