Here I will list all desired Web APIs and their browser support to have a rough idea of what browser support do we want for the next major release.

• ✔ flexbox gap
  Safari Desktop: 14.1+ | Safari IOS: 14.5+
• ✔ BigInt
  Safari Desktop: 14+ | Safari IOS: 14+
• ✔ :is()
  Safari Desktop: 14+ | Safari IOS: 14+
• ✔ <input type="datetime-local">
  Safari Desktop: 14.1+

• ❌ FocusVisible
  Chrome 86, Safari 15.4, Firefox 85
• ❌ :has()
  Chrome: 105+ | Safari Desktop: 15.4+ | Safari IOS: 15.4+
• ❌ <dialog />
  Safari Desktop: 15.4+ | Safari IOS: 15.4+