Rust and Scratches
It is a silent killer
Rust is a big problem. If your set gets rusted, you have to clean it and remove rust completely, otherwise it will be dangerous to use!
Depending on the type of steel, of course. Stainless steel is an answer to that, but not every manufacturer is on the same page here. Rust still appears on our knives and scissors if left unattended for a few days. I noticed that kitchen knives from Europe, such as Zwilling Henckels or Wusthoff, get rusted more often than knives from Aisa, like Mac, Shun, Nagomi, and others. Nothing but a personal observation.
Rust thrives if you keep your knives near the kitchen sink or other high moisture level places. It is a chemical reaction where water and oxygen get in close contact with iron in a knife, causing iron to oxidize. It doesn't happen fast but can be quite distractive in the long rung.

Rust is manageable if timely treated with the hard side of a dish sponge. But if you are the one who loves having a ton of knives, but uses one or two from the whole set, rust may appear unnoticed and cause quite a lot of damage. If that has happened to you, think about the necessity of having a big knife set. How often do you really use each knife? Do you think you could shrink the number of knives down? I, personally, prefer to have no more than four to five knives in my set. Each knife in a set this big will be used and washed regularly.
Currently, I have two chef knives where one is a heavy-duty knife that can cut through bones or even a can of tuna if needed, and the other chef knife is pretty much for everything else. Among those two, I also have a Nakiri knife for vegetables, cheese, and other soft food. Two prep knives for boning, peeling, and cutting. It is a good set where each knife regularly gets used and has a good knife sharpening service. My choice is Japanese brand knives, they averagely lighter than knives from Europe, and normally don't have a massive bolster. Japanese knives keep a good balance between the handle and the thin elegant blade.

I got these two in 2017. They worth every penny!
But the other side is that Japanese knives typically cost more than their European competitors.
Scratches matter from the esthetical point of view rather than from a practical point. As long as you are not cutting through a metal sponge or something that can damage the blade, not likely your set will ever get scratches on it. Deep scratches are hard to get removed, to the point where it is unreasonable to remove them at all. If you keep your knife away from bad hands and take care of it, it will serve you for a long time.

I find it attractive when a knife has a little bit of shine. I got a polishing wheel and attached it to one of the grinders I have. I love the result that I get from it! A polishing compound on the wheel helps to give the knives that light shine.

After I started including rust removal and polishing in my knife sharpening, my customers noticed a huge before/after difference. Their cooking experience got better now they look forward to using their knives again. I cannot be happier to see the positive feedback from a customer a few weeks later after visiting me. It means I move in the right direction.
Keep your knives dry and clean, it is not hard to do.