Because the real issue is that we have no diversity of supply.
1) We have allowed everything to become monopolized such that losing a single supplier knocks out large chunks of supply. At this point, it is quite clear that for economic robustness, any company found to control more than 25% of the market for any product should be repeatedly broken in two until that is no longer true. But that would require robust anti-trust enforcement.
2) The suppliers are Always-Late(tm) Inventory optimized such that they can't absorb a significant uptick in demand without a long wind up time. Covid comprehensively demonstrated that industrial producers no longer have the ability to "retool". By removing as many humans from production and replacing them with automation, the productions lines have traded any flexibility for maximum profit.