Well put and explained. As a person who has a history of codependency, this really hit the nail on my head. I experienced a lot of this toxic behavior growing up my family. It’s very confusing because there’s a complex line of when do we show a little flexibility for our partners (as we would expect them to do back for us) out of caring for them for various issues, and when are they fully taking advantage of us.
I ask these questions to give me guidance around what lines to draw.
Would they be willing to do for us what we do for them at another time?

Are they being abusive?
Are they asking me to do something they can do themselves?

It’s so annoying, how toxic people use anything they can to manipulate healthy relationships. Even their own trauma can be used as excuses. It’s so evil.