BigQuery select * except nested column

The way to think of the problem is that you still want a payload column in the result, but you want it to have a different structure, namely to exclude comment. In this case, you can use SELECT * REPLACE to make the modification. For example,

#standardSQL
SELECT * REPLACE ((SELECT AS STRUCT payload.* EXCEPT (comment)) AS payload)
FROM `bigquery-public-data.samples.github_nested`
LIMIT 1000;