This is going to be long but hopefully it'll give you some detail and perspective.
All I can tell you is how the company I work for does it.
We have blog posts which go back to 2014 and any number of them are outdated (for example, they might refer to a business that is no longer a client, that sort of thing). They're also not too terribly well-written.
As a result, my team and I (I'm the Content Manager, so I'm in charge of, among other things, the blog) are auditing the entire blog. For really old stuff, some of it is being updated and the writing is getting tightened up. If there are big changes, we'll announce at the top that it's an update. That way, it doesn't look like in 2014 we were talking about a client we didn't get until 2018 (we're not psychics!
). For others where it doesn't pay, we'll leave them alone.
We choose the topics to update by if either they are answering common questions we get from clients or they've got decent search traction. But with a five-year-old blog post which doesn't answer any questions and no one is searching for, we just don't bother.
Currently, those don't need to be archived as they aren't big. But I imagine eventually we'll pull them completely off and set up redirects from the old URLs to newer, better, more current content.
If/when we do that, we most likely won't need to retrieve that stuff, and might even delete it outright. But if we really, really
needed to keep it (if in the one in a billion chance any of it was part of a lawsuit), we would need a server for just that stuff. And that can run up costs. So for us, it most likely wouldn't be worth it.
For businesses which have to hold onto older content in archive format, they can conceivably buy server after server. If it gets expensive, they might even hire some company to handle that ancient content. I imagine there are companies which do that (I have no information on the specifics of that). But you can see how this can run into the thousands if not millions per year. For many businesses, it would pay to audit their old content and at least get rid of duplicates in an effort to cut costs.
As for the images stuff, we have an in-house design guy who is actually in Bangladesh (so his time zone is something like 12 hours off mine). We buy stock images from sites like Shutterstock and, if there's a way or a reason to modify them, he does that. So I might want him to add wording and he does that.
Last week, we were working on trucking content and we had a great picture of a guy in a truck, but the truck was red. No big deal, except we have a branding guideline and we favor more blues, cool greens, and grays (which are the kinds of colors most people associate with financial services companies). So he used (I am guessing) Photoshop to change the truck's color from red to blue. For wording, I'm pretty sure he uses Adobe InDesign. I also have InDesign (I had it when I was hired; the company doesn't pay for my copy although they might pay for his), but I don't do designing as he's far, far better at that than I'll ever be.
I don't know if he created the update of our logo. I know the logo was originally bought from a contractor on Fiverr. But I doubt the update was done the same way. However, I'm not privy to how that was done, so I can only guess.
Images are stored in lots of places, including via WordPress (which is how the blog is put together). For non-blog stuff, it's probably still stored via WordPress and, ultimately, somehow via our hosting company. Once we have a lot of stuff and things start to really slow down, we'll probably weed through it and discard or compress a lot of the images. I know on the older posts, they weren't compressing the images, so that's another reason we're auditing the blog.
I realize this is probably a lot more than you wanted to know, but that's how we do it here. And now if you'll excuse me, I need to get back to it!