‘The cloud’ is just a different datacentre
As a few have said, using a cloud service (whether SaaS, PaaS or IaaS) doesn’t take away the need to think about recovery processes etc, although recovery testing can be more complicated.
The top level admin who had the rights to do this probably would have had similar abilities in an ‘on premise’ world - delete all the VMs/clusters, delete everything in AD, delete all the passwords, delete the encryption keys used for backups etc etc. Only a delegation of rights that separates rights over separate areas prevents this, but its not uncommon for the top admins to have rights over everything.
I guess maybe the difference is that you could have someone with very little experience as your top level Gsuite administrator. But if it was done deliberately by someone who, say, just got sacked, the fact its a cloud service is not that relevant. The company just has someone else they can try to put the blame on, and possibly less chance of scavenging around for fragments of data...