I don’t know if anyone still makes the pencils. IIRC they used a special formulation for the graphite that reduced the dust and risk of breakage, but I don’t think there’s much market for that outside the space program since that’s about the only place the dust would float and be hazardous. The pens were in development even before the space program because there’s a market for pens that can write in unusual orientations. I’m sure the marketing of it being a pen used in space helps expands that market some, but the market would exist regardless. It’s supposed to be a nice pen to write with also, although I don’t know how much of that is kind of a placebo to justify spending $10-20+ on a pen. I’m sure it’s nicer than a 50¢ pen, though.

Felt pens can be prone to leakage, especially in lower atmospheric pressure. This can be a problem even in airliners, and definitely not what you want in space. There’s nothing in the pen mechanism to seal the ink in when not in use. A properly made ballpoint pen actually seals the ink in when not in use. That was Bíró’s big selling point over earlier technologies like fountain pens; the pen still writes even if you leave it uncapped and the ink doesn’t dry out. The Bic pen was revolutionary for creating a manufacturing process that could produce them cheaply.