Good question about the office. We use .doc files, which althought they are MS they are written and read by most everything. And PDFs. And text. My IT guys say I gotta use Excel, and when moving stuff around we use CSV, text, etc. In other words, stick as much as possilble to anything non-proprietary.
Photos are even a better example. They HAVE built in standards for metadata via IPTC, exif, XMP and DNG. That covers considerable ground, but not adjustments from RAW. But you can use TIFF or JPEG. You only lose the PIE data; meaning you lose you stored parameters for image adjustment. You didn't have to do that; you could export. Maybe it's easier for those of us that remember negatives and printing; prints were unique. Like an export. If we did it again, stuff might change no matter how many notes we took or tried to stick to the same equipment or chemicals or paper. Many of us didn't think that was a minus.
LR can hold just about as much as you can put in; the limit is usually elsewhere. I've corresponded with people with over a million images (IMHO people with that much stuff should move to real databases, but that's another question). Yes, moving that will be awful. Which is why I'm suggesting that perhaps people shouldn't get themselves into that situation...again. The ONLY info in a PIE like Aperture or LR that is proprietary, and hence stays in Aperture or LR, is the parameters of image adjustment. Again, you can export the finished image. What you lose is the ability to take those parameters, like a blueprint, to make new exports (and generally most of us adjust images so as to export or use them, not simply look at them in Apertuer or LR). But you can still process a new image from that original RAW. All the other organizational info can be retained via the metadata in the images themselves. I replicated my Aperture project/folder/album structure just using keywords; it required a bit of moving around in LR but it wasn't that big a deal.
I have no doubt there are situations where one has to store lots of adjustments in a PIE and there's no way around that. Maybe you have clients who want the same image with slight variations over and over. Fine. In that case choose a solution that is more likely to last than Apple's stuff. And prepare for it. We did that with WordPerfect; we had tons of templates and stuff and knowing we'd probably lose it we set up workflows so that content was saved as text, so that it could be reused in new Word templates/styles with minimal editing. That also meant we could make use of new features, as one can in new DAMs that have better RAW processing than Aperture, for instance. It was a bit annoying at times, but it also meant we didn't have to try to do mass conversions of WP documents when we finally went all Word. Lots of people are dealing the adjustment issue by exporting just jpegs of versions to LR; they then use the JPEGs as visual exemplars of what they want but process the RAW anew. They might get better results, or they could use the Aperture exported image.
In fact many can get by without the need for a PIE at all. After Shot Pro, eg, works as both a browser, and can store stuff in a library. It can write it's own XMP with image adjustment info, not using any database.
Aperture was in a class by its own for perhaps a few months. It's been in competiton with Lr since almost the start, and with many others since. I know lotsa of people are both very (over?) committed to it, and love it, but it is not unique in any fundamental way. This or that tool works better or worse, some like the RAW processing Apple does, some don't. I suppose a managed library is kinda unique, although I don't see how. It's just a big package. I used Aperture a lot, and still do, but people have been moving off it for a long time, and complaining about Apple killing it is just more wasted energy.