It seems like the only way you can truly make yourself unoffshoreable is to acquire your own local customers by running your own business.
I agree. If you aren't your own boss, then you are vulnerable to offshoring.
And if you are your own boss, you risk being fired by your customers when your products/services cost more because you use local workers. Offshoring destroys jobs now matter how you work.
Indeed. I've been running my own business for nearly two decades as a consultant for local home users and small businesses. Bigger businesses ALWAYS employ their own IT staff, but there aren't many bigger businesses in my local area.
10 years ago I was making substantial income - $250k one year! Today the business turnover is pathetic. I used to supply hardware, but gave up that business because there was no point competing with large retailers who obtain much better prices than I do. Decades ago, people paid thousands of dollars for computer systems. Now a thousand bucks can buy them two! There is also a decline in computer users in favor of smartphones, which are even more disposable. A common thing I hear is "should I fix this or just buy a new one?"
So, I've gotten a job at a supermarket and actually make more money than I was recently in the business. I'm really enjoying that job too because its quite physical and has lots of interaction with other people! I'm also now at university to eventually join the police force (possibly in computer crime). Both are jobs that cannot be offshored.
To conclude: my advice is, find an employer who won't offshore due to their security requirements (law enforcement, government, banks), or find a different career path.