I use Terabox and it works just fine. As with any cloud storage, your data is only as safe as the company itself, cloud storage comes and goes whether you pay for it or not, over the years I have seen cloud storage companies pop up and also just disappear. Also, your data is only as secure as you make it, NEVER rely on any cloud storage companies promotion of "Encrypted Space" ALWAYS encrypt your files yourself BEFORE uploading. With that said , some rules to live by when using cloud storage ....
1.) Redundancy is key, especially if you are uploading important stuff. If you are unable to store your files locally, always, always upload in multiple cloud locations, like I said , cloud services come and go, most without warning.
2.) This goes for any cloud service .... use a STRONG password, if they offer 2FA or passkeys, USE IT, If you have bio metrics capability , especially if using any cloud service on a phone app USE IT.
3.) I live by the code that to never upload anything to the cloud that you cannot afford to lose, this is why redundancy is crucial with important files. Upload a household or company spreadsheet , family pictures .... or even your favorite porn for that matter, if that cloud service goes belly up without warning , your files and pictures all go bye bye, there is no recovering them , if you don't have them stored locally or on another cloud service , they are never coming back.
These days physical hard drives are way cheaper than cloud storage when you do the math, which is what I really steer people towards, barring someone breaking into your home or office and stealing those hard drives, your data will be much safer stored that way, one can purchase an 8TB external hard drive for a fraction of what you would pay for just a couple of TB's of cloud storage per year.
Like I said, I use Terabox, I don't pay for it, I don't pay for and never have paid for any cloud service. Terrabox offers 1024GB of free space which is more than any other free space I have seen so I don't need to worry about running out of space. Everything I have stored on it , if Terabox went belly up tomorrow the loss would be no big deal.