Money

I'm concerned we've gone from support to condemnation.

He does as she pleases because.... he's got Florence Nightingale complex?
Is that something we'd like to extinguish?
Or is it just he should be focused on a more appreciative less entitled target of his kindness? (at least until his wife adopts the appreciative trait?)

The term in psychobabble circles is "boundaries".
There needs to be a limit past which lessingham will not be pushed and for everyone's sake (including his wife) he needs that boundary to be less demanding than the one he has now (if there is one. Lessingham? Have you found yourself holding your ground before? What was it? How did it feel?)

Clearly he'd like to stay, and I'd put it to him that setting a boundary shy of resentment will help that marriage last so he doesn't just walk off one day. Good, solid boundaries are healthy for both caregivers and the cared for. 

It could, long term, be a loving act to say "No" consistently to unreasonable / obnoxious demands to keep resentment in check.
Identifying unacceptable behavior is a skill that may need strengthening and maybe Lessingham hasn't had practice. Perhaps the rest of us have enjoyed upbringing or life companions that have given us a head start on what we all take for granted? Life courses that have so many of us shaking our heads in puzzlement. Having lived his life, maybe we'd act similarly. Supportive online friends may be a nudge to that lifeline that brings him out of the role of punching bag/dumping ground. (with kindness to both himself and ultimately, his wife too)

I have now been reading for years lessingham’s complaints about how mean his wife is to him and how she treats him like dirt. Each time he seems surprised. I have read little from him that indicates he is trying to find ways of making his life happier such as using “no” when his wife demands that he bow to her wishes. I see little evidence he is attempting to find activities and friendships that reduce his dependence on his wife. And, yes, even in the pandemic it is possible to use Meetup and other methods to enrich one’s life and expand one’s social circle.

At some point one is responsible for one’s life and wellbeing no matter how one was raised. At some point it is important to take responsibility for one’s life. Incessant complaining indicates he thinks he is helpless but that is true only if he chooses it.

I may have related this before. Ehen I went into therapy my therapist said she normally helped raise self esteem. With me she was going to have to find it first. I do have low esteem and almost non existant boundaries. For me, saying no is actually kind of a huge thing. But for today I will do it. Maybe if I pretend and act as if I have boundaries, I may even develop them.
On the money front I will do as I wish today and screw her.

Lessingham, feel the fear but do it anyway was my path to setting boundaries.

Mirrororchid post is good advice.

Started small. I bought a book on self esteem and will work through the programme.
We had a discussion about lingerie as she was buying new knickers. I insisted she bought a basque as well. She thinks they m ske her look silly but I said I loved them so do it for me. So she did.
I bought a new jumper, (sweater for Americans?) not my style but I liked it and thought why not.
I mentally bathed in money. All the things of desire of my youth I can now afford!

Demanding respect is a bit like "The Talk".

It should be backed up by a prepared form of consequences.
If the disrespect continues, what are you ready to do?

My wife had the hardest time with my daughter's abusive behavior. She finally avoided her 24-7.
It took months for my daughter to realize things has changed after 19-20 years.

Demands for respect with nothing to back it up, can garner even MORE contempt. The abuser knows they wouldn't put up with what they give you and think of you as their inferior for that reason on top of whatever else they were judging you for before that.

Having no consequences for disrespect can, as the phrase goes (baza again? ironhamster?), "shred your cred". I guess a demand for respect is it's own kind of "The Talk". More general, but I can see a result just as dramatic all the way up to divorce. Demanding respect may ruin a lot of the value you have to an abuser. Sick as that sounds.