Backblaze is terrible, but you will likely only find out when you need to restore.
When backup excluded some files, they blamed antivirus software and recommended to go without.
They actively deleted their only backup because the client couldn't read the original files (which was due to disk error).
They admitted that there isn't any guarantee or even effort to make the backup consistent - after asking me to explain the concept.
The only reason I still have my data is because of the very expensive cleanroom disk rescue that they of course refused to pay for - because why try to do what you can to compensate for failing at your only job?