Suggestion

Consider whether we should raise tsconfig target / lib from ES2017 to something higher.

We're already planning to increase requirements for v6 including:

• chore: drop support for ESLint v6 #5972 (released 2019)
• Drop support for NodeJS v12 #5917 (released 2019, EOL 2022)
• feat: bump minimum supported TS version to 4.2.4 #5915 (released Feb 2021)

This all seems to indicate people would have a relatively modern environment to run TypeScript linting in.

The newest possible we could use is ES2021, is that too new or is there any reason we couldn't use that?

This may be a breaking change that could be included with v6 (#5886).