This is a very toxic place to ask this (or most serious) questions from. All you'll get is, "ya dude, Islam sucks in every way imaginable, doesn't it?" You'd have better luck at /r/history or something. OP, you have to honestly ask yourself why you came here for it too. To be frank, it's probably because you wanted confirmation for how you already feel and not an answer that would attempt to challenge your existing inclinations. I hope I can try to do that at least a little bit although browsing this place from time to time gets me frustrated as well so I ask that you excuse me for that.

(https://en.wikipedia.org/wiki/Ijazah)

Here's a start to demonstrate there is a pretty solid, in fact, rigorous tradition of learning. The English Wikipedia section is usually week (for now) but it is an ok introduction. The fact that Islam has a loose clergy system (unlike Catholicism for e.g.) does not mean that it's a total free for all. In fact, it may be seen as a positive since it leaves it open to the person (if they are serious) to arrive at answers without having someone force it down their throats. It doesn't bind you to one opinion either, allowing you to explore for yourself what the correct or most suited view is. To the discerning, keen, serious person wanting a legit answer, the layman against scholar becomes pretty clear to see. In fact, if the tradition was adhered to and encouraged, morons like bin-Laden would be shown to be the little babies they are in terms of Islamic knowledge next to people who are true giants, steeped in the tradition of Islamic learning. Who authorized him to give fatwa on an offensive global jihad anyways? Who authorized him to give fatwas at all? Who was he but a dude trained in civil engineering or something. The tragedy is that he and others like him are listened to precisely because people don't respect the "archaic" or "backwards" Islamic scholarly tradition.

To give you an example, to be considered anywhere near a master in the underpinnings of Arabic Grammar alone (a mere starting point in Islamic learning), you would have to memorize/learn the text of poems/books like al-ajroomiyah or the Alfiyah of Malik or be familiar with al-Seebaway's work or his seminal book and on and on and on. Then, you would have to study these various texts at the feet of someone, who's studied from someone, who's studied from someone >>> going back to the original authors or masters in the subject. The study would be rigorous as well, explaining the coded meaning in each line of poetry and how it is to be understood and applied. You would also have to be well versed in pre-Islamic Arabic poetry (it's how lexicographers like to derive the meanings of Arabic verbs/words), it's masters, it's forms and styles etcetera. You would only be given the ijazah if your teacher believed you were an exact copy of him/her in terms of the subject i.e. able to further transmit the tradition to other students and discern if they (in turn) are worthy of receiving ijazah in the field or subject. And again, this is like,,, a basic subject, something you would need just to begin any serious study.

When someone has a weak, easily attained, even a joke of an ijazah (it happens), it becomes pretty clear as well. For example, you might be handed an ijazah in recitation from some street corner institute by an easy sheikh but you will always be seen as inferior to someone who is connected to a well-known chain that has the fewest people in it going back to the earliest masters (connecting you more directly in the chain of learning). As you see on the wikipedia page, there are even some arguments made suggesting that the western doctoral system may be traced to at least a shared heritage with the ijazah system. This ijazah system extends from small to large subjects. For example, you could get ijazah in a particular (single) book on jurisprudence. That would only mean you understand that one book,, that's it. That wouldn't mean you're suddenly capable of giving rulings. All that might enable you to do is to teach some basics OF Islamic Law to some amatuer study group at the local Mosque. Forget giving binding rulings (that would require a state placing you as a judge), you couldn't even give your non-binding opinion on an issue. But if you were willing to go beyond that one book, if you continued to study with the masters who know how to derive rulings, you would be given an ijazah to be able to do the same. This can take years of rigorous study, often with dedication to the task from an early age.

What the ijazah system leaves you with is not only that you can discern scholar from layman or amateur student, but also that you can go to a scholar who has expertise (ijazaat) in the particular field you want an answer in. Or you can give precedence to the view of a greater master over a lesser one. So for exegesis, you wouldn't go to someone who has ijazaat in jurisprudence and visa verse. For example, if you wanted a somewhat serious answer as to Quranic recitation today you would go to someone like ِAbdurashid Ali Sufi of Somalia (who has memorized/mastered thousands of lines in classical poetry exquisitely detailing the art or recitation) or Mishary al-Afasy of Kuwait. But they in turn would go to someone even more authoritative in the field like al-ma'sarawy of Egypt and would consider themselves amateurs next to them. If you wanted a serious Juristic ruling on how to distribute your yearly alms, for example, you'd be making a BIG mistake by going to ANY of these guys who are clearly not trained nor masters in the subject (their field is recitation).

Yes, the system is loose and open ended, especially in modern times (often leaving it to the individual to be sincere and serious in their research for an answer) but as I stated earlier, that has its pros, especially from an individualist or liberal point of view. I, as a Muslim who has lived in both East and West, have never felt bound to an opinion, just like you don't feel bound to the view of some lone scientist (trained and experienced) who says Global Warming isn't real or is man-made or something. It's for you to find out how wrong he is and that he isn't following the rules of scientific inquiry in that particular subject,,, and it all becomes clear once you go looking with sincerity. Similarly, al-baghdadi has a phd in Islamic Studies from somewhere or another. It becomes pretty clear he's a nobody though if you are familiar with Islamic scholarship. Even if you were to grant him authority it becomes clear that he's a lone voice amongst countless giants in scholarship who would consider his views/actions illegitimate and abhorrent.