I think the reason is there are a lot of tech / tech-adjacent workers on Reddit and they know people less than 100 miles away (in the USA) are doing the same job as them, possibly at the same company even, but are getting significantly higher compensation packages.
US immigration laws are a complete non issue for tech workers (at least in my experience). Mostly, people I work with seem to not want to move the the US for the same reasons people don't want to move to another state: they're happy enough where they are, they'd be leaving friends/family, they're worried if the move that their life will be worse. They already make enough money to be comfortable, if not inordinately wealthy.
I suppose my consideration could be different if I got a job that paid > $150k or something and could actually take it, but the recession is here and the job market is dead, and so far it hasn't crossed my mind to try and make it possible, so I'm going to continue draining my savings while I look for a job here in Vancouver that will probably be below $130k CAD
We have very different views of the US though. I felt the same as you when my only US experience was in the Bay Area, but after living in Chicago for 5+ years and having visited a bunch of places around the country, I miss a lot about American culture now that I'm not there.
Regarding the degree, it was less a matter of whether people care, and more about the actual visa. Perhaps a two-year diploma is more workable; I only have a 1 year technical diploma from a Uni, and although I haven't aggressively pursued getting across, it doesn't seem like I'd meet the requirements with it. Would be curious though, because the job market is truly shit here atm.
Just took a short road-trip down through Washington and Oregon, and really enjoyed my time. You're right in that I didn't think much about the difference until I got down to the Bay Area. I do think there is some sort of imbued mega-capitalist eat eat eat buy buy buy nature to many other places though that just sort of vibes me out sometimes, and maybe some airports are an example of this; almost a volume difference.
I noticed it for the first time when passing through the Minneapolis airport of all places. Felt like there was a hundred neon signs flashing at me to eat some burger or get a pedicure while waiting for my flight. Every table at a particular restaurant had an iPad right when they came out. While we have Cabela's and Bass Pro Shops, there's are basically theme parks. That kind of thing; it's not everywhere, in-fact it's probably a rare feeling I get, but it's a level of excess that's hard to feel comfortable around.
What you're hearing isn't accurate. Rents are going up in Tokyo, not down. Sure, there's a bunch of abandoned houses way out in remote rural areas, but no one wants to live there (for good reason). Housing prices do seem a lot more stable than in Anglosphere nations, however, and they're constantly building new housing (and knocking down old buildings to make way for them). Just like many other places, the population is concentrating in the big cities, so the population is generally rising there. However, unlike the US in particular, the Japanese yen has fallen a lot in value during the pandemic, and combined with recent inflation, this might have something to do with the recent rise in rents.
It's clearly a global structural issue. Low interest rates are a pan-national commonality - and they can take a lot of blame for part of the situation we're in now. But they don't explain housing shortages.
Population growth probably plays a big part - housing is always going to be lagging population growth. The various stories I've seen about Japan - with low rents, falling house prices and large numbers of abandoned houses - seem to map with the falling Japanese population. "Things were better in the 70s/80s/90s" probably partly just means that the ratio of houses to people was better. The population of most major western cities was falling or flat through much of the 70s and 80s - leading to the situation where my parent's generation all seem to have snapped up large, well located houses for not very much money.
I'm fully supportive of the idea that, with all things equal, if we build more houses then supply and demand will drop prices. But if you allow unchecked population growth (which in the UK and Canada seems to be primarily caused by immigration) then the amount of building required is effectively infinite.
I've visited the Toronto area from the UK more or less every year since I was a child, and the overwhelming story is one of huge development. The change in the suburbs of Toronto over the past 30 years has been vast and unlike anything I've seen in the UK. Yet that clearly hasn't been enough to stop house prices going crazy as well. The net effect, though, is that there's miles and miles of sprawl and 6 lane streets dominated by cars. The answer definitely isn't to build more of that. The population of Canada has grown by 40% in the last 30 years.
Population growth combined with an ageing population and the kind of rights purchasing a house gives you in the west create increasing inequality driven by land. That seems to be the underlying issue that's driving city house values up everywhere.
There are possibly some answers. In the UK in the 60s-80s we built entire new cities, with the land purchased by the government at agricultural value so that the entire uplift was captured by the developers rather than speculators.