There aren't very many good reasons not to be backing up to the cloud these days. Unless you are banned from doing so by some law or regulation, have a metered Internet connection or no Internet at all, you really should be backing up to the cloud.
A good backup is essential
A good backup can help you recover from so many potential disasters, it's basically a no-brainer. It can save you hours of work and a lot of stress, headaches, and heartaches by helping you recover irreplaceable files and databases from corruption and deletion (accidental or intentional), file system corruption, file sync errors, hard drive failures, database corruption, lost devices, stolen devices, ransomware infections, and more.
A cloud backup has some important benefits that a local backup does not
A cloud backup is still accessible after a fire or natural disaster that destroys everything. A local backup will be destroyed along with everything else.
A cloud backup is still accessible if both the computer and its attached backup device are lost, stolen, or destroyed.
A cloud backup will typically provide some protection from ransomware infections. A local backup will usually be encrypted along with the original files, rendering them useless. Many cloud backup solutions also provide some form of ransomware detection these days.
Yet, some people still aren't backing up to the cloud. Why not? Let's take a look at some common excuses/misconceptions:
I don't want to pay money for cloud backup/it's too expensive.
Cloud backup is actually very affordable these days. For example, Backblaze Business Backup gives you unlimited backup for only $50/computer/year. That's a very small price to pay given all the potential disasters it can help you recover from.
I don't trust putting my files in the cloud.
This is my favorite. The truth is, you already trust the cloud every single day. You use email for business, right? Then you're probably trusting at least two cloud providers with every single email. Chances are, you bank and shop online as well. Again, these are cloud services. So, if you trust your email, banking, and credit card transactions in the cloud, why are your spreadsheets, Word documents and PDFs any different?
I don't have anything worth backing up.
This probably isn't true. If you really stop and think about it, you probably do have some files you'd really rather not lose forever. Pictures, for example, are often irreplaceable. Small businesses may have signed agreements, customer databases, accounting databases, receipts, invoices, employee records, emails, notes, scanned documents, and more. All of this information has value to your business, and losing access to it forever might range from inconvenient to devastating.
We already back up locally to an external hard drive/flash drive.
Good for you. Now start backing up to the cloud. While a local backup may be better than nothing, it's only a slight improvement. Most ransomware infections will encrypt the contents of any connected hard drive or flash drive as well as network shares that it can reach. Also, your local backup will do you no good in the case of a fire, natural disaster, theft/loss (of the computer and the attached backup device). A good local backup can be a nice complement to a good cloud backup, but if can only pick one, you should probably pick the cloud backup.