I'm not sure if a cloud version could ever replace access. Access is already paid for, works with on premise data, is easily deployed (no browser version madness), is ubiquitous, is easy to recover from bus factors (search the victims computer for .mdbs) and is easy to control access too.
Salesforce seems like a particularly bad solution, you end up with a small army of high priced, low skilled salesforce contractors and a heap of vendor lock in.
Yes you are right, one minor point though, when people build things in Salesforce the 'source code' is all there and visible (apart from installed third-party packages) and so 'bus factors' are about as easy to recover from as with Access - and there are plenty of Salesforce contractors around. I've seen some organisations kick big consultancy firms off of their salesforce system and then just continue building it themselves.
Salesforce seems like a particularly bad solution, you end up with a small army of high priced, low skilled salesforce contractors and a heap of vendor lock in.