There's nothing inherently bad about big tech. However most big tech does bad things. Currently, the vast majority of them are engaging in heavy censorship, and manipulating the information we see or don't see.

As previously said, it's not inherently bad, but the current situation mainly comes from the money value the market places on private personal information that it can then use for marketing and sales purposes. Couple that with the idea that they are mostly based on the West coast in places like Silicon Valley and Seattle, and we see politics injected into the process. This definitely becomes an issue with social media, because all the arbiters of truth are basically citizens of the most left-wing places in America. Most people are not so tech savvy, so they don't necessarily know they're getting fooled, and even if they do, they are tacitly okay with it because they are too lazy to learn new tech or research alternatives. They are comfortable with this bullshit, and this further fuels the fire. Not a good combo overall.

So, the idea is big tech runs all the systems and all the data required by the government. Think of it this way; if Lockheed Martin designs and builds all your big, bad weapons for your military that can level a country or even the planet 100 times over but they also could sell the same *products* to other entities. Now military contracts for companies like Lockheed Martin typically bars them from selling that tech to other countries and individuals keeping the US a top military. Now big tech: Apple, Microsoft, Amazon, Google, Facebook has government contracts today, but they sell to *everyone*, consumers, the US Government, private businesses, organizations, terrorists, and even China (gasp). Also, not just iPhones, AWS, and Office... AI/ML, quantum computing, holographic targeting systems, things that can unlock a weapons or flight system from Lockheed or a connected nuclear submarine, or a metro power grid in a few seconds. What has happened really is the government has figured out the value of Big Tech and realized they are running un-checked, with no contracts, no Hippocratic oath, or loyalty pledge.