What makes tape sound better than vinyl ?

Bigger, or fuller, or both is the right term, I think. Smoother too.
Cassette decks also have very slow speed. But for a cassette some Naks and Tandbergs are very impressive, especially with Vertex tape and no dolby. And that's with captured lamp power cord.
Ralph is a little attached to vinyl but he knows what he knows.
Orpheus10, when I am ready I will almost certainly go after Studer. The most important reason is transport. But also other things, including the availability of parts and of tuners who could make it almost like new. It should last me as long as I do, at least.

@orpheus10  That’s all well and good but in the OP he says he is copying vinyl onto cassette. So we can eliminate reel to reel from the debate. Fair enough? The OP question is a general one, is there something about audio cassette that would make a vinyl copy superior to the original vinyl, you know, sound quality wise? We don’t have to compare audio cassettes to reel to reel or vinyl to reel to reel.

On the contrary, this thread is about open reel decks and tape, I only mentioned cassette as an example of a 'mini reels'. 
We can compare anything to anything.

Fair enough. But that’s not what your OP was all about. A cassette is a mini reel? Interesting.

I have to take issue and disagree with your basic premise. Tape doesn't sound "better" than vinyl it sounds different, you may prefer those differences but it doesn't actually make it better it's just a matter of preferences after all there are people who like the sound of Bose speakers , and that doesn't mean they sound better. Just saying.