Mass job loss won't happen because it will harm the economy and laying people off is expensive. Instead less people will be hired which will also harm the economy but at a much slower pace and gives time for society to adjust. Many jobs were also never technically needed but companies are incentivised to grow. The headcount of Microsoft grew by roughly double in the past decade which never meant double the productivity. Part of it is, the employees are the moat. Even if they don't need them, they don't want them to start their own companies or to move to other companies.