1. No network latency, you do not have to send anything across the atlantic.
2. Your get privacy.
3. Its free, you do not need to pay any SaaS business.
An additional would be, the scale being built-in. Every person has their own setup. One central agency doesn't have to take care of all.
And related, if there is no service, then the service cannot fail to secure your data.
No possibility of a billing or login error, where you lose access to your stuff because they just think your're not current or valid when you are.
No possibility of losing access because the internet is down or your current location is geo blocked etc.
No possibility of your account being killed because they scanned the data and decided it contained child porn or pirated movies or software or cad files to make guns or hate speech etc.
Those overlap with free and privacy but the seperate point is not the money or the privacy but the fact that someone else can kill your stuff at any time without warning or recourse.
And someone else can lose your stuff, either directly by having their own servers broken into, or indirectly, by your login credentials getting leaked on your end.