The only exceptions I can think of were when people gave multiple months of notice that they were going to quit and already had declining performance due to e.g. unhappiness about the job. If you're not performing well and you tell your employer that you're quitting in a few months, they're not really interested in giving you more paychecks to perform poorly. IMO, that's not exactly unreasonable either.

Some companies will restrict the employee's access for the notice period and remove their work as a way of protecting company information from last-minute exfiltration (it happens a lot more than you'd think), but those employees are still paid during this time period. They're also obligated to answer questions and attend meetings about handoff, although in some cases this may amount to zero work.

But no, it's not common for US tech companies to fire employees immediately for resigning. I don't know where the parent commenter got the idea that this is common.