1. It has no value or prestige within the frum community.
2. It meets the legal requirements for a bachelors (“first”) degree, so any program that says “you need a bachelors” without being more specific will be satisfied. Thus, in theory, a BTL and the right courses could get you into medical school. In all fairness, most graduatge programs require any bachelors and no more. However most graduate programs require specific courses (among other things), and a yeshiva won’t offer such courses but they could be taken at a secular university.
3. In some cases, if you can prove you’ve spent four or more years in yeshiva learning full time, a graduate school would say that is the equivalent of a bachelors. It’s up to the school.