I suppose you're right to a degree when it comes to supermarket doors and some car locks, the idea that things should be so connected is certainly already present, and there's no reason to expect it not to saturate wherever it can. But there would remain real value to the low tech approach for a number of reasons. Physical locks are less expensive than networked locks would be. Networked locks would be subject to the vulnerabilities that come with being connected to the internet and being run by software, whereas physical locks wouldn't. I think Bruce Schneier said 'complexity is the enemy of security' (if not I'm sure I'll be corrected) and the analog stupidity of physical locks is what makes them useful. Although granted, physical locks can be hacked too, and are, I'd submit that the networked variety would likely be no less vulnerable to physical attack, and still more vulnerable to attacks over the network (so, implicitly, less secure.)

A ubiquitous system for locks that somehow can identify you by proximity, can also be used to track your movements and whereabouts. Networked locks could be theoretically controlled from a remote location, leaving someone else to act as, essentially, the systems administrator for your physical access privileges. This is what they do in prisons. Applying the concept of separating someone from direct control over their physical access-space to a large scale, and it looks a bit ominous - at least if this assumes these network locks are also commonplace on cars, houses, hotel rooms, hospital rooms, etc. This is not even considering what happens when power goes out, or the network goes down. Physical locks still work without electrical power, and the tumblers only care about the piece of metal that's currently jammed into the slot and whether it moves the pins properly... principle of least privilege.

I can see this sort of thing becoming somewhat more commonplace but I also see its spread as self-limiting. E-books aren't going to replace physical books, the internet isn't going to replace television, which hasn't replaced radio, which hasn't replaced theatre. In each case, the newer version of the technology does provide their own advantages and enhancements of the medium but not to the degree that the older, less complex version no longer has relevance. The future is never going to be that evenly distributed, this I believe. In a hundred years, some people might be genetically engineered posthuman cyborgs linked to a quantum hivemind, but someone, somewhere, will be living in village of mud and stone. People will still use physical locks because there's no real reason for most people not to. They could theoretically still work in a hundred years. Software doesn't age nearly as well as a steel bar through a door jamb.