Some major highlights of TypeScript 4.4 are:

Control Flow Analysis of Aliased Conditions and Discriminants
Symbol and Template String Pattern Index Signatures
Defaulting to the unknown Type in Catch Variables (--useUnknownInCatchVariables)
Exact Optional Property Types (--exactOptionalPropertyTypes)
Class static Blocks
tsc --help Updates and Improvements
Performance Improvements
Spelling Suggestions for JavaScript
Inlay Hints
Breaking Changes