With rising costs, there is an increased need to carry larger and larger amounts of cash. $100 bills have become less viable as the top level currency. We need to bring back the $500 & $1000 bill.
Most people these days see very little actual cash and perform all of their transactions electronically. There are still many people who prefer to deal in cash for reasons of personal privacy.
There is also good reason keep the unneeded fees out of the hands of banks and credit card companies who get a cut of every electronic transaction, taking much needed money out of local communities all in the name of providing convenience.
By bringing back large bills, the use of currency will rise. The net effect will increase buying power and create needed stability in times financial uncertainty.