By comparison, a Safety Razor is much better. It has one blade so the line is exactly where you place the blade, and it doesn't clog. They are also cheap as chips, so I can buy a brand new blade every day and still come out better than buying cartridges, meaning I never use a dull blade.
For others, it might be just a slightly better shave or cheaper, but if you have a beard I'd say there is literally no reason not to use one.
I've cut myself precisely once with mine after a couple of years, less than with a modern multi-blade razor (although, admittedly, that's not a fair comparison as my first shaves were with that type of razor). In general, you cut yourself because the blades are too dull so you press too hard, with the blades so cheap I use a new one every day so it's always sharp. Maybe different people with different skin or hair types might have more benefit from them, I guess.
My current set up is a Shavette that cost £8.50, a brush that cost £7.50 (at half price), blades that cost £3.70 for a pack, and shaving soap that cost £10 (lasts for ages). I've tried more expensive stuff and have come back to this setup because it's simply very good.
What is the point here? Yes, Gillette gives away cartridges to try to get you to buy their razors. Yes, actual single or double edge razors are much better if you take the time to learn how to use one instead of buying the latest "7 GODDAMN BLADES ON THIS THING SHIT CAN YOU BELIEVE IT YOU'LL BE SO SMOOTH" bullshit.
So what? What is the point here? I don't see one.
Also, 'learning to use one' is a bit strong. It's not exactly significantly different. It's more like 'a little more hand control required' than a skill you are learning.
I was traveling recently so I thought "oh I'll give that Harry's company a try" and wow was it painful! It was like being clawed in the face by a cat. Not even marketing saying that your still disposable razor products can seperate you from the fact that you are a disposable razor product.
So I will keep my safety razor and just check the bag at the airport.
Two annoyances.
First, they are not TSA friendly. You cannot put them in carryon luggage.
Second, I get the best results when using an associated shaving brush and shaving soap. Shaving gels and foam don't really do it for me anymore.
However, if you do want to get a few more shaves out of a 10 cent razor, you can always strop them on an old pair of jeans.