Cloud is not just for sharing, the benefit of cloud is the redundancy in their infrastructure. Its very unlikely for their storage servers to go down, so your data is much safer with them than any device you own.

External hard disks can fail, the larger the disk, the higher the impact/loss of an external disc. If you want to spend a bit of money upfront, set up a NAS with at least 2 drives to reduce your chances of failure.

Best solution is actually to use microsoft onedrive. M365 comes with 1TB of cloud storage per user. Personal plan is about RM300 and family plan is about RM400. You get access to the microsoft office suite as well, so a pretty good deal. After 1TB the price is expensive.

Depending on your back up purposes, you might also consider just directly storing the data in AWS S3. You can choose the infrequent access tiers like glacier if you don't access the back up data often.

For starters, the cloud back up should not be your only back up. So don't rely on it 100%

If you scared company sell your data, just make sure its encrypted before storage.

For 2TB, can go up to 2k depending on the level of the problem. RM600 is only for problem like partition failure. If other problem like disk damage, head damage, etc. The cost is higher.

External SSDs are good if you plug them in often, even if they hit their write threshold you should still be able to read from it. However as a long term back up, they are a very bad solution. If you keep an external SSD unplugged for a long time, the loss of charge over time will lead to data corruption. SSDs are essentially RAM, they have mechanisms to hold the charge longer, but its not indefinite. SLC based ssds can retain data longer (~10 years), but MLC/QLC might only have a span of 1-2 years, your mileage will vary.

You have the means to do a good back up strategy, so my advice is you do a simple set up.

[pc/laptop/external ssd] ---> [NAS (e.g. Synology)] ----> [Cloud backup]

For your NAS, get a 2-4 bay and make sure its mirrored. You'll only have 1/2 capacity of your drives but you will be very resilient against hardware failures. Any drive fail, you can just buy a new one to plug back in to rebuild.

Then for cloud backup, go with a service like backblaze.com which is 6USD/month/TB.