If you are looking for data security, and want to minimize costs, there are a few options that does not require cloud storage.
If you are not in a location that is prone to massive natural disasters, then consider doing a RAID 1 or RAID 5 setup in your PC, and then use a NAS (you can build or purchase a NAS (building will be cheaper).
Then if you need offsite backups, consider using some of the syncing functions and see if you can get any other extended family to also set up a NAS, then simply share the storage (you can encrypt the backups if needed).
One issue with paid cloud storage, is when you need to store lots of video and raw files, the monthly fees quickly become a horrible value, this is why I avoid it. For the price of a cloud service, I can literally gradually tile the walls of my house with WD red hard drives.
The issue with cloud services is when you need to backup 15-25+TB of data, cloud storage gets expensive.
Furthermore since most of the cloud services that focus on the consumer market, also have data limits, a large scale backup or restore can take months. Many will wither cut you off or throttle you significantly after a few hundred GB.
While building up local redundant storage has a higher up front cost, in the long run given the lifespan of modern drives, it will easily pay for itself compared to a cloud service within a few years. Furthermore, the local storage route will have more functionality. For example, My NAS build is connected via 2.5GbE, while not as good s internal storage. the mapped network drive to the NAS is fast enough to edit photos and video over the LAN. I can mount a system image and even launch a PC game over the NAS and it runs decently. If there is no DRM, and all modified data is stored in a local folder (such as the app data or saved games folder), them multiple systems can access a single game install from the NAS at the same time.
The flexibility is unmatched compared to cloud storage.
Beyond that, I share the storage with a remote NAS, thus off-site backup with my brother, thus each NAS acts as offsite storage of the other.