This topic is a lightning rod and it seems we're conflating a bunch of things. All these things can be separately true.

1) H1B's are abused
2) Immigrants, like any other people, can form cliques at work
3) Companies do layoffs while simultaneously hiring
4) H1B semi-indenture the hired immigrant

First off the bat, this is a clickbaity article. The literal implication is FANG laid off and FANG also hired H1Bs therefore FANG laid off Americans to employ lowly-skilled H1Bs. This is pure sleight of hand. Facebook's had ~20k layoffs and ~3k H1B hires. It'd be easy to claim a wholesale clean out/swap out if Facebook successfully hired ~10000 to 20k H1Bs. Secondly, H1B hires usually include a mix of net new hires (say a college grad joining facebook) and existing employee (I work at facebook and want to switch to an H1B visa). Thirdly, H1Bs are usually lodged independently of layoffs or better put, H1Bs are lodged several months in advance. A decent chunk of those H1B hires started their application process 16-18 months ago. You cannot just fire someone and immediately pick an H1B. The H1B process is independent and nondeterministic (or random because it takes several months to process an application & it all depends on the lottery). It's pretty blatant the article doesn't even mention the number of visas awarded. It also doesn't even bother backing up the 'low-salaried' claim (fun fact, all H1B salary info is public so you can actually do the math yourself and see if say Amazon's H1B salaries are 'low'/'deflated'. Spoiler, no such thing)

(I'll also add, the energy required to perform a conspiracy of multiple managers coordinating to mass replace american workers at FANG could boil the sun. I think labor collusion happens i.e. a do-not-poach from X company, but H1B would be practically infeasible at distributed semiautonomous Google/Facebook hiring teams. But hey, I guess it's doable but not worth the RoI)

Secondly, H1B abuse definitely happens and we literally know who the obvious culprits are. These are the standard offshoring culprits. I'm not going to mention them by name here but they are responsible for most of the horror stories you hear i.e. having an american train their literal replacement

Thirdly, I totally get it. Tech is a tough-to-hire industry and hiring is a zero sum game (if i were an economist, i'd argue the productivity gains from a diverse skilled workforce actually makes the pie bigger but that's for another day). If I were American I would be pissed off at the idea of a bunch of foreigners coming in and taking my jobs. But that's not what's happening in this article.

The last thing is the almost xenophobia which I don't think should be relevant to H1B hiring, but idk folks. If a PhD team is full of a bunch of folks from Bleurgh, of course the Bleurghians will clique up. It's naturally human tendency especially if you're a foreigner. I literally see Americans do this wherever they go :). But sometimes some people do experience stone-wall cliques where the Bleurghians refuse to even attempt to assimilate. That's a complicated issue, but I can see why it'd be frustrating. I once took a graduate CS class that was mostly full of Bloopians and I found it amusing when the instructor would sometimes conduct office hours in Bloopian

Honestly the best way to fix immigration is to be mad at your government and compel them to make common sense regulations. We literally know who perpetuates H1B abuse but the USCIS doesn't have the means to fully stamp it out. USCIS is woefully understaffed and inundated and like any government bureau, pretty slow. The government, because of partisanship, has been pretty much roadblocked on common-sense immigration for decades.