Describe the bug

vue-cli(webpack) VS vite

Reproduction

https://github.com/BuptStEve/vite-css-treeshake

• npm start to run vue-cli

• npm run vite to run vite

• npm run build to run vue-cli

• npm run vite:build to run vite

System Info

System:
    OS: macOS 11.4
    CPU: (8) x64 Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
    Memory: 2.44 GB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 14.17.1 - ~/.nvm/versions/node/v14.17.1/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 6.14.13 - ~/.nvm/versions/node/v14.17.1/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  Browsers:
    Chrome: 92.0.4515.107
    Safari: 14.1.1
  npmPackages:
    vite: ^2.4.3 => 2.4.3

Used Package Manager

yarn

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/vue-next instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.