The thing is, there's no such "best" steel. It all depends on what you want to do with the steel. I'm sure a custom maker will make a MagnaCut chef's knife, but I don't think you'll notice much of a difference. The corrosion resistance should be great, and that goes a long way with easy of maintenance, especially when cutting things like tomatoes. But most kitchen work is done on a cutting board (hopefully plastic or wood), and the material is quite soft. You can make a good argument that MagnaCut isn't needed in the kitchen.
MagnaCut wasn't developed for the kitchen. Even though I am a self-professed "knife person" I just don't rely on a knife all that much where I would notice the difference between MagnaCut and VG10. So, on paper, MagnaCut is a big step forward compared to pretty much every steel. But that doesn't mean every steel is not obsolete. And, of course, we all have preferences. We like what we like, even if another option is "better" in some way.
52100 is a great steel. Sharpens like a dream. Sometimes, that's all that matters to a person.
A (probably) completely different question: are there good knives for a kitchen that doesn't require maintenance? (So, are the ceramic knives any good?) I cook once in a blue moon, mostly pasta; so I'd use it mostly to cut cheese and sausages. Can you recommend a knife for this? (Or maybe it simply doesn't matter on such a small scale?)
A remotely-decent stainless kitchen knife on non-fiberous materials will last long enough that you don't really have to worry about it.
Especially for such soft materials as cheese and sausage.
Vegetables are the problem for sharpness, and meat-with-bones the problem for toughness, assuming careful handling.
So, yeah, with care to not bend it, a ceramic blade will do well on things like carrots, while a simpler stainless steel blade handles your cheese and sausages just fine.
But even then, a very simple high carbon blade with a simple automatic-angle-keeping sharpening tool (10~20$) only needs to not see the dishwasher and receive oiling before storage.
Which is basically the extend of "have an oiled sheath to store the blade in".
French Opinel makes cheap (5~15 $) (but rather practical) pocket knifes out of (traditionally) such carbon steel. The wooden grip is more sensitive to water than the blade, in my experience.
No, there aren't. Knives dull over time; even the most durable steel formulations need sharpening eventually. Those ceramic knives are pretty robust, but they too will dull. More importantly, they're extremely brittle; my experience with them is that they chip very quickly and are really unsuitable for anything other than very light use. For your use, they might be ok, but I think you'd end up being annoyed when they break sooner than you want.
I recommend something from the Victorinox Fibrox line to folks like you who just want to cut stuff and not think about knifes. They're very sharp out of the box, quite durable, and will last a long long time before going dull. When they do, they're so cheap (like $25) that you could just get a new one rather than messing around with sharpening.
Although beware, those pull through sharpeners are notorious for doing a terrible job sharpening knives. They take off far more material than needed and tend to produce an edge that isn't very sharp. YMMV.
When I think of maintenance, I think more about corrosion resistance. Is the knife 100% dry when I put it away? Do I want to take the time to wipe down the blade when I cut acidic food items? Then I think about sharpening. How long can I wait between sharpening? How long must I sharpen the knife? VG10 is a good knife steel for the kitchen. It is a Japanese stainless cutlery steel. You can find this steel on mass produced knives (Tojiro) and on many custom knives, which can be quite expensive. VG10 has good corrosion resistance, decent toughness, sharpens well, and can hold an edge a decent amount of time. An inexpensive combination King water stone is up to the task of sharpening VG10. It also does not take an inordinate amount of time to sharpen VG10. As a comparison, Magnacut will do everything VG10 does but better.
Another benefit of VG10 is that you often find it in knives from Japan. They understand that geometry cuts, so they tend to use thinner blade stock (but their knives are not brittle) and they tend to heat treat to 59-60 HRC. I think these knives are a good all-around package. Again, Tojiro is a good brand to start with.
I have a $5 rectangular chef knife that I got in Chinatown. I'm sure knife nerds would consider it crap, but it works fine. I have to sharpen it now and then. Dunno if that counts as maintenance. The simplest way to sharpen a knife is with a slack belt sander. I don't have one of those so I just sharpen it freehand on a cheap stone. No idea what I'd do with a fancy knife if I had one.
I have a self-sharpening stainless steel kitchen knife made in Czechoslovakia with waved edge. It never sharpened, but it still works just fine for everyday kitchen needs, except for peeling (I have a ceramic peeler for that), because of the waved edge. However, I have no idea where to buy a second one. «Bread knifes» with roughly similar edge are large, thick, and non-flexible.
MagnaCut wasn't developed for the kitchen. Even though I am a self-professed "knife person" I just don't rely on a knife all that much where I would notice the difference between MagnaCut and VG10. So, on paper, MagnaCut is a big step forward compared to pretty much every steel. But that doesn't mean every steel is not obsolete. And, of course, we all have preferences. We like what we like, even if another option is "better" in some way.
52100 is a great steel. Sharpens like a dream. Sometimes, that's all that matters to a person.