I'm glad you won the fight you were fighting. I lost most of mine, and this was 5 years ago.
A few things worth elaborating on.
> 10 core SMT xeon with 128G of RAM for everyone in the team
In our case, most frontend web devs realistically use macOS or some other unix env. Not only did our bunk-ass windows machines suck spec-wise, and in terms of physical dimensions, they also sucked because they were windows based. This was shortly before WSL, so it was a pain. The DevOps guy did have a crazy machine with tons of ram and so on.
> I cant build in less than 10 minutes
This was literally the case for me every time I made a change. Sometimes the previous result would be cached and I'd need to do it again. I was constantly fighting a stupid battle, and nobody really understood why things were the way they were or how to change them, including the java devs that had been working on it for years.
I kind of won the dev machine battle, because the VPN wasn't really sophisticated and I just set up some system on my personal mac, against the wishes of management. When a designer came in, they got a mac, and had to ask me how to connect it to the VPN.
> it was possible to get either a light java subset running just the frontend to test, or make the js independent for testing, yes with a yarn soup lol
Someone had set up a node instance that attempted to replicate the output of the java system, but without some bits that I can't recall atm. The inconsistencies and trying to maintain a one-for-one replica was just as much of pain. If I remember correctly, that was in part because there would really have had to have been a deliberate time investment in creating a sustainable replica that involved communication when any data changed server side. It was a crap-shoot, and I should give myself more credit for lasting as long as I did, but less credit for not jumping ship way earlier.
I ended up literally burning out, getting fired, and didn't find employment again for years. I have it on my resume that I did a few things successfully while I was there, but quite honestly I don't completely remember what those were, and am just guessing at this point.