What makes tape sound better than vinyl ?

Unfortunately that is not the question, which one is better. It’s why vinyl copied on tape sounds better than the original vinyl. It is possibly related to the question, why do CDs copied to CD-ROM sound better than the original?

Geoffkait, let me be most specific; I was referring to my deck which is a 2 track. One of my posts explains the differences in the size of the heads in 4 track and 2 track. The heads are larger in 2 track than 4 track. The playback of the 4 track will be identical to the record. The play back on the 2 track will be identical to the record, except the sound will be bigger because of the playback heads. That doesn't only go for the records, it also goes for you speakers, they will sound bigger because the source is bigger.

A small screen TV may not be better than a big screen TV, but you can see and enjoy more detail.

Think of the fundamental difference between a cassette deck and a reel, assuming high end in both cases, the reel sounds better mostly because of the larger heads. In the past, most decks were 4 track allowing you to record and playback in both directions, thereby saving money on the cost of tape. 2 Track records in one direction and that's it.

Since what has been recorded on 2 track is the same identical information that's on the record, you may not consider it better, but bigger sounds better to everyone listening.

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.