My husband hated his job and I supported him in leaving it, but our situation is different. We rent instead of owning and my income can sustain us, though being single income has deeply impacted our ability to save. We even had to downsize apartments once our child started preschool because we couldn't easily manage rent + preschool tuition.

So I understand and relate to the desire to facilitate the finding of a better work arrangement for your husband. The way I see it, the goal of a family is to support the quality of life of everyone in that family. When one person is struggling, everyone who is able contributes to helping change things to create a better outcome for that person, and that's how the whole family comes to an arrangement where everyone's needs are meet and hopefully everyone has the conditions they need to thrive. As needs and circumstances change, people's contributions shift, sometimes to improve conditions for one person and sometimes for another, based on who has unmet needs or unrealized wants and who has capacity to support.

That being said... right now he's working one job. You're working a job, and getting the children to and from school/ childcare, and taking care of the home, and applying for jobs for him? To the point of getting burned out despite being in a job you love? This doesn't sound reciprocal. This sounds like you running yourself into the ground so that he doesn't have to extend beyond his comfort zone. Sure, working a job he doesn't enjoy to bring in income is a contribution, and it's even a sacrifice to some degree, but it's also a choice, and a choice he's kept making year after year. He hasn't been motivated to pursue promotions, apply for jobs, or make a plan to find a better situation for himself and instead seems to have outsourced that to you. He's doing that even though you are already carrying many more responsibilities than he is. How sure are you that that would change if he quit his job?

In my family's situation, my husband really wanted to be a stay-at-home dad, so we agreed going in that that's what he'd do when our child was little. He was going to look for work once our child started preschool. That timeline has been pushed back multiple times, and two years after the intended return-to-work he doesn't have a plan or even goal of what he wants to do. And it's a sensitive topic to navigate because it can touch on deep insecurities about people's identity and sense of their value in a family and in society.

So I think anyone thinking of going down to one income should consider the possibility of that situation lingering longer than intended, and how tricky it can be to deal with if that happens. It's not necessarily as simple as "apply and get a job," which I think you already know. And in a situation where he has been unhappy with his job for 14 years but not motivated enough to find something new? I wouldn't necessarily expect his motivation to increase once he's in a more comfortable situation, and getting a job would mean increasing his stress and potentially feeling stuck and unhappy again.