I could have written all of your posts myself- bar a few details such as me not being male or a lawyer. Dh is a kiwi and I have been here for 8 years, we have 3 dc together. I am also terribly homesick for the uk. It's not bouts, but more of a gradual, increasing need to move back.
Like you, I tussle with the fact we are comfortable financially, have a naice house with large garden, good schools and a happy childhood for the dc full of outdoor activities, friends and space.
Our commute is 10-15 mins and I am lucky enough to be able to work part-time in a senior position in a job I love.
I really do appreciate these things- we are lucky.
BUT and it's a huge but, I'm just not happy here. It's beautiful, there is space and freedom, but it's isolated, parochial, expensive and somewhat backwards. Hard to explain without sounding like an arse, but truly, you feel like you just don't exist here sometimes, there's so little going on, and so few options.
The uk? I miss the architecture, the countryside, the choice, the opportunities, the feeling of being in an exciting hub, the history and strangely the supermarkets and tv. Most of all I miss my family and friends.
We have discussed moving back to the uk, but dh has lived there before and didn't like it. He doesn't have a problem with the people, but with the weather, 'tiny houses' overcrowding, litter, etc. He does recognise a lot of those things will be minimised if we weren't in a major city.
I could probably convince dh to move back, but is that fair on the kids? Or him? Like you op, would our life really be any different? Would it actually be worse?! Is my 'homesickness' actually the very normal strain and stresses of having 3 young dc that will manifest in other ways when I get home? Not sure.
Sorry I haven't been much help- but just wanted to say I feel exactly the same.
I think perhaps the solution is to get stuck in, and enjoy the good things, and try to get home as often as possible to get a 'fix' of the things you miss. That's what I have put in place anyway!