Rejecting infinity because it is vague versus accepting other vague concepts

peace!
The discussion here this week about the possibility of ‘something’ that is a taste itself raised a question for me. I saw in the thread on the notebooks site, regarding questions about why infinite regression is impossible, that you wrote, among other things, in the comments:
“I felt it was enough for me to point out that the concept is not well-defined and therefore cannot constitute a philosophical alternative. In other words, the burden of proof is on the one who proposes the regression. You cannot use a vague concept and reject another proposal on its basis. As long as the concept is unclear to us, it cannot be used even if theoretically it could exist in some other sense.”
“Infinite may be something that is not defined to the end (this is the problem of infinity in general), but in an infinite regression of explanations (a chain) there is another problem beyond the definitions of infinity, and that is that there is no presentation of an explanation here, but only a statement that there is an explanation.”
“Cantor’s theory deals with the infinite as concrete entities, and this has been criticized. It seems to me that he does not define infinites but deals with the relationships between them and assumes that they exist. But when we try to define them, we run into contradictions or at least a vague interpretation. On the philosophical level, it is enough for us that the interpretation is vague to claim that the claim that infinity contains no real alternative proposition.”
Why do we reject infinite regression because it is an undefined concept (and therefore an invalid answer), and on the other hand, do we not reject ‘taste itself’ for the same reason when we encountered the question of who created the Creator? Why is it different here? ‘Taste itself’, which is a reasonable thing, is also a vague concept that we do not really know how to describe, and yet we bring as an answer to the difficulty of stopping regression ‘who created the Creator’. According to the same logic, it should also have been rejected.
I know there are other difficulties with infinite regression, but this is precisely the main fallacy that most philosophers would agree with. That is, in order to avoid a vague concept, we introduced another undefined concept. What am I missing?
And on this occasion,
Happy and kosher holiday to the rabbi and all his family!