Sorry to hear your experience.
I have had some my work on DropBox for more than two years already. I was the guinea pig for this experiment. Our small company have had all work on DropBox for a year now. I just went and asked from one of our trusted workers how has it been for him. He said it have worked great. I have the same experience with him.
I can't say that it has been _totally_ flawless, but pretty much though.
A couple of times it has happened that there was a problem with saving. No crashes though, and you could continue saving later.
I am not sure about the techniques used by DB, but I believe DB makes some invisible helper files for cloudsync or something. So you can save while cloud is syncing too. If that helper file is in the middle of it's making, you might see errors when saving. But then again, I don't know for sure.
I don't hit the save button too fast, at least not with big hundreds of megabytes sized files. And everything works great.
I really wouldn't want to drop DropBox out of my or my companys workflow. It's great to have _everything_ avvailable to _all_, almost realtime and from anywhere. You are upto-date even on the road, presuming there is internet available of course.
We do have project files, publish-folders, text-documents, libraries, AC installation files on the cloud.
I can copy-paste a link to a publish folder to our clients, and they get the newest documents downloaded. No need to try to send email attachments, and I can be sure they are the altest - no matter who ever published them.
Now that we are mostly isolated and work mostly from home, this is even more important. I can trust I have the latest project file with me at home, and at work. Now that we are opening the country again, and possibly begin to have meetings at site again, I have all of the latest files at construction site too with my laptop. There is no need to worry if I remembered to take them with me, or remembered to move them to cloud service. At the hotel room I can work with the latest files and they just miraculously sync. One less repetitive and error prone task to worry about.
Our DB plan also keeps backups of our files, so in case of a human error, you can go back. It reminds me of Apple Time Machine a bit. I do have my own backups too, of course.
We are on AC 22 though. I haven't tested this thoroughly with AC 23, not yet.
I really don't want to abandon this workflow anymore. This has become essential for us.
AC25, Rhino6/7+Grasshopper, TwinMotion • Mac Pro 6,1 E5-1650v2-3,5GHz/128GB/eGPU:6800XT/11.6.5 • HP Z4/Xeon W-2195/256GB/RX6800XT/W10ProWS