The repo's tsconfigs declare "lib": ["es2018", "dom"] (root and base; tsconfig.build.json says es2019) while target is es2020 and every supported runtime — Node 20+ in CI, the browsers Angular 21 supports — provides ES2022. The Angular CLI generates new workspaces at ES2022.

The understated lib makes tsc/IDE reject standard APIs (e.g. Object.fromEntries) that the shipped code can use freely.

Proposal

Declare lib: es2022 across the tsconfigs. Declaration-only — compilation targets are unchanged, so emitted code is identical.