I don't think any competent senior engineer would say that backups are too expensive without looking at the actual cost first. Your example doesn't work though

I don't think any competent senior engineer would say that backups are too expensive without looking at the actual cost first. Your example doesn't work though - using someone's laptop is likely not secure, reliable, and definitely not appropriate for any compliant data. It really doesn't meet the actual requirements of a true backup. My backups sit on disks that supports disaster recovery, are proven to be reliable, and meet all compliance requirements for the data we store.