But then you need someone to maintain/look after that automation, and they'll be more expensive than two Brendas

And now if one of the Brendas wants to change their process slightly, add some more info, they can't just do it anymore. They have to have a three way discussion with the other Brenda, the automation guy and maybe a few managers. It will take months. So then its likely better for Brenda to just go back to using her spreadsheet again, and then you've got an automated process that no longer meets peoples needs and will be a faff to update.

For the record, I wouldn't usually use Brendas as a collective noun like this, it feels a bit wrong, but my aim was to make sense in context of the above comment.