Flutter widgets so confusing

Question

Why is flutter widgets so incompatible with each other?

Why can't have const TextField inside Row's children?

I'm using sliverboxadapter as parent to below widget.

Column(
      children: [
        const TextField( // IF I PUT HERE NO EXCEPTION
          textAlign: TextAlign.center,
          decoration: InputDecoration(
            border: OutlineInputBorder(),
            hintText: 'Enter answer',
          ),
        ),
        Row(
          children: [
          const TextField( // IF I PUT HERE ERRORS
          textAlign: TextAlign.center,
          decoration: InputDecoration(
            border: OutlineInputBorder(),
            hintText: 'Enter answer',
          ),
        ),
            ElevatedButton(
              onPressed: () {
              },
              child: const Text("Check"),
            ),
            ElevatedButton(
              onPressed: () {
              },
              child: const Text("Refresh"),
            ),
          ],
        ),
      ],
    );