Major version angular updates should be done with ng update.
npm update for updating angular minor/patch versions has a downside: it will also update other unrelated packages.
You can use npm-check-updates to update just specific packages and you can choose to target patch/minor/major versions.
This command will update all angular package minor (and patch) versions (but it will keep the major versions):
npx npm-check-updates --upgrade --target "minor" --filter "/@angular.*/"
That command gives you a preview of the new versions and updates the package.json accordingly:
Afterwards you can run npm install.