I have a Lamy 2000, Pilot Vanishing Point and some other highly recommended pen (can't remember the name, it was a few years ago) and they are all scratchy as hell. Absolutely not as nice as even a cheap ball point...
That depends a lot on the nib, plus how it has been finished. And perhaps more importantly, and easier to change, paper and ink.
My vintage 146 M nib is incredibly smooth on some heavy papers with Iroshizuku Konpeki ink. So smooth I was tempted to look into details. It turns out Konpeki ink has tons of lubricants. Even different ink colors from the same manufacturer make a difference. And some alternatives make the setup not smooth at all, quite scratchy indeed.
Try changing inks and paper. Worst case, you might need to send your nibs for adjustment if you want different behavior. If they are small, particularly the VP, you may not be able to get a really smooth experience.
I can second your experience, but you are also using some very "affordable" pens as far as nibs go. The Lamy entry level pens are great design, but their steel nibs are painful to write with. The VP is a wonderful engineering feat, but the nibs are smaller than their equivalently named European versions (I found writing much nicer with a Euro F and a Japanese M, for example).
Ink and paper do make a difference; coated papers make things glide but the ink may run. Some papers soak too much ink making globs. Some inks tend to dry out in the nib or flow poorly.
So, I've had bad experience with each of the above, but I also have now set my expectations to a better level. And sometimes you do get surprised (I got a Pelikan Stola III somewhere in Europe for around $40 and it was really nice; some info at this random site: https://www.penchalet.com/fine_pens/fountain_pens/pelikan_st...).
So, yeah, low end stuff varies. But worth experimenting because when you find a good one, it makes writing fun again.
Which size nib are you using? If it is Extra Fine (EF) or Fine (F), then it can be scratchy. Moreover, Japanese EF and F are generally smaller than other EF and F.
I have a Lamy Safari F, which is super smooth and glides. My Pilot Metropolitan also has F, but not only is it thinner/smaller but it is not as smooth. I won't call it scratchy but it could be construed as such.
Also, paper matters. Fountain pens generally prefer a smoother paper, especially one that doesn't absorb much ink.
You will also need to see how you are holding the pen and the angle the nib strikes the paper. You may want to search online for some advises on that since that can make a world of difference.
Edit: Almost forgot, the more you write the better a fountain pen gets since the nib adjusts to your writing habit. I had an old Waterman when I was in high-school, which I don't have anymore, and so far no pen has come close to it in smoothness.
That depends on the nib and ink. I use a KaWeCo pocket fountain pen with an extra fine nib, and Montblanc ink, and it writes as well or better than the nicest Japanese ball pens I have tried.
I also like the pocket-pen format. I seldom lose a pen since it lives with my keys and wallet. That pen, plus a thin crosshatch notebook I keep in my back pocket means I can take notes much faster than on my smartphone. Then I photograph my notes. Google Lens is getting scary-good at recognizing my idiosyncratic writing.
Sorry to hear that, it's horribly frustrating! I know it can happen, I had the same experience with my first pen. It did improve after I re-bent the two halves of the nib and used the bottom of a ceramic mug to smooth the tip of the nib. But getting a new pen was the only solution that really worked.
If you're sure you're holding them correctly, so the problem is not the posture, try to buy either pens with a guarantee from the manufacturer (so you can get it fixed), or a pen in a shop that will let you try it first. Not all nibs are manufactured equal...
A good pen should glide much better than a gel ballpoint.
Then something is wrong with your pen, or you're trying to write on paper towels or something.
If you look into fountain pen communities you'll find the VP in particular is popular because of its quality at an approachable price point. It's the equal of many more expensive pens in my collection -- and nobody would confuse any of them with the experience of using a disposable ball-fed pen.
In general, there's three reasons why a fountain pen would be scratchy: it's got a very fine point (European EF or Asian F or EF), it's a broad stub or italic with a sharp corner that requires changes to your writing style, or there's something wrong with it.
The short answer is that there's probably something wrong with them. If you want to make the effort, YouTube has some instructional videos on improving them; you'll need some very fine abrasives such as very fine micromesh. I recommend SBREBrown.
I also have a Lamy 2000 and a Vanishing Point. For a long time I didn't use the Lamy very much as it was scratchy compared to the VP. At some point I decided to stick with it and now it gets used most days for work notes and the like. With use it has got much smoother -- it might be worth persisting. (The VP is still more practical for everyday use but just doesn't hold much ink -- and so tends to run out at inconvenient times.)
I have a Lamy 2000, Pilot Vanishing Point and some other highly recommended pen (can't remember the name, it was a few years ago) and they are all scratchy as hell. Absolutely not as nice as even a cheap ball point...