You are probably going to get conflicting answers.
First of all, there is a sense in which nothing is “stored in the cloud”. There may be exceptions, but all the cloud syncing software which I’m familiar with stores your data in a special folder on your hard disk (at least while you are working on it) and then sync the data from from that special folder on your hard disk with a second copy of that folder in the cloud. If you have a second computer, there is a copy of the same special folder on the second computer’s hard disk that is synched with the same copy in the cloud. This has the practical effect of syncing three copies - first computer’s copy, cloud’s copy, and second computer’s copy. The first computer only works on the first computer’s copy an the second computer only works on the second computer’s copy.
Assuming all this sort of just works, you have to give the two computers and the cloud sufficient time to sync up any time you switch between computers.
The recommendation is usually not to operate in exactly this manner. The reason is that most of the cloud solutions will be trying to sync between your current computer and the cloud the whole time you are working in RM. Your RM database is updated continuously while you work. It’s not like where you working in a word processor or a spreadsheet program and your data is written to disk only when you File → Save. RM has no File → Save and your data is written to disk continuously. The continuous sync will cause heavy disk and network activity on your computer and can sometimes cause data corruption of your RM data.
The official recommendation from RM is not to keep your RM database in the cloud folder. Rather, keep you RM database outside the cloud folder and store your RM backup files inside your cloud folder. When you exit RM, ALWAYS ALWAYS ALWAYS do a backup. When you start up RM, do a restore and NEVER NEVER NEVER do an open.
An alternative which is not recommended by RM is always to pause your cloud sync service while you are working RM and to resume your cloud sync service when you exit RM. You still need to wait for the cloud sync service to sync to the other machine before switching machines.
It’s always safe to keep your media files and your backup files in the special cloud sync folder. Some users keep their RM database in the cloud sync folder without pausing the cloud sync service while using RM and they swear there is no problem. But there really is.
One other factor is that cloud sync services don’t absolutely have to keep all three copies of the special folder all the time. They offer the option of syncing just in time - just as you open a file - to save space on your hard disk. I personally recommend most vigorously against this approach. I think you as the user need to have all your data on your local machine at all times. But if you disagree, that’s your choice. In any case, I think most of the cloud syncing services to default to keeping all your files on your local disk at all times in addition to having a copy synched to the clouded. The important exception is that OneDrive defaults to not keeping your data on your local disk at all times. So if you use OneDrive, I recommend overriding the default so that all your data is kept on your local disk at all time.
Lots of users do what you are talking about doing very successfully. I have done it successfully for years with both Dropbox and OneDrive.