Best advice here so far.
I have a collection of vintage DE razors and they are all different. My favourite is a 1951 Gillette Tech. It’s just the right level of blade gap for me. Others may like different razors, everyone’s face and beard are different.
In general, I have found that newer DE razors tend to be more aggressive than older razors. So someone getting nicks with a modern razor may just have one that is too agressive.
It might be worth getting a late 50’s - early 69’s Gillette adjustable to learn what works best. You can probably get one cheaper than a new Merkur on eBay, or at a flea market or antique shop.
Blades also vary widely between and within brands. Do you need the sharpest blades on the planet??? Probably not. You have to experiment. Get a sampler pack from some online store and try them out.
Soap is a big factor. Don’t just go with what’s on the pharmacy shelf. Buy a tube of a premium brand like George Trumper to set a baseline of how a really good, slippery soap works. Then find a cheaper brand that performs as well.
Technique counts, obviously. I find that a 3 pass shave is overkill personally. Once with, then once against the grain with some spot touchups works fine for me. Just don’t skip the “with” pass if you don’t like razor rash.
I can get a “baby bottom smooth” shave with a DE. Is it better than what I could get with multiblade plastic razor? I don’t know.
What I do know is that those multiblade heads cost around $4 each, and my preferred DE blades cost about 8¢. Not to mention that there is no plastic in sight, and the amount of waste is minimal.