Not really... he's been working on the startup for 7 years. Let's assume he had an average salary of 150K during those years. Plus he got $3.7M on the acquisition (it's not clear from his post if that's what he takes home or if it's pre-tax). That's 4.75M.
Now let's assume a senior engineer in FAANG with a an average salary of $350K for 7 years. That's 2.45M. That's a very rough comparison and not taking into account taxes (the FAANG engineer is likely to pay more money in taxes overall).
But the bigger difference is how he spent those 7 years. He spent it building and managing his own company with all the freedom in the world. Compare that to a senior engineer in FAANG...
Update: someone in the comments mentioned he'll likely not need to pay any federal tax on the acquisition money. That makes a huge difference and the take home gap is much larger than my initial estimate.