While using import and export locally I realised that export is many times slower than import which made no sense to me.

I noticed two things:

1) The progress updates are not happening at 250ms intervals as we specify here, but in fact seem to happen in a tight loop (probably every row?):
https://github.com/mongodb-js/compass/blob/92270b35885e90f6eb7b153275848f7a2be21278/packages/compass-import-export/src/modules/export.ts#L501-L511

See https://mongodb.slack.com/archives/G2L10JAV7/p1669366262289589

2) At least locally in development the dev tools console breaks during export of large collections. You have to close it and reopen it to get it to work again. I logged every time we update the progress and only the first few logs would show up even though the progress keeps updating.

See https://mongodb.slack.com/archives/G2L10JAV7/p1669369902773209