I'm not certain that "commonality" you refer too ever really existed, at least not to the extent we were all taught about The Great Melting Pot that was the United States in elementary school.
Immigrants, even the ones from the "Non-Shithole Countries," as the former president referred to them, took generations to fully assimilate. There were over 1,000 German language newspapers in the country in the 1890s, nearly 200 years after Germans started arriving on these shores and still 75 years after the great immigration wave of the 1820s. These papers lingered on, with most of them shutting down due to World War I but others limped along into the 1940s. In the 1880s there were 5 German language newspapers in Cincinnati alone.
I read once that the US was the fourth largest Spanish speaking country in the world. I don't know if that's true, but I bet we were once the second largest German speaking country in the world.
My point is that even the people most of us here would recognize as sharing "commonalities" didn't come here and just automatically become good Americans. It took generations. Who's to say the experience of the Latinos -- documented and undocumented -- will be any different?
The economic despair you reference, too, is not unique to California. Here in Montana, in the western part of the state, partly fueled by the popularity of the Yellowstone TV series, there has been a flood of wealthy people the last several years driving home and rent prices out of the range of normal people. Many there are sleeping in cars campers.
Don't apologize for the doom and gloom. It's appropriate.