I've been a KU subscriber for more of the time than not, but always when I could get a Prime Day or other good deal on the subscription. (This is what has caused the occasional brief pause in my membership - waiting for a good deal.) What I like about KU is that if I find a new indie or Amazon-published author I like, I can binge read a whole series for free - well, technically not free, but already paid for. I also like the chance to try some new authors/series risk-free.
And it's not completely true that well-established or traditionally-published authors are never on KU. Sometimes they are doing new series that they are self-pubbing, or they are writing in a new genre with a different publisher, or sometimes they will get the rights back to early titles that have been out of print, and decide to self-pub those. And often those will be on KU.
I guess the biggest exception, off the top of my mind, is JK Rowling, whose Harry Potter series, once it was finally available in e-book, is on KU. But mostly it's true that famous authors or books aren't on KU.
With that said, at full price, I would never do KU, but at the discount prices that come from time-to-time, it's worth it to me.
For the OP, since rumors are abounding that Prime Day will be in mid-October, maybe it's worth a free trial until then to see if you like it, and then get a discounted subscription for Prime Day if you do...
And as others above have said, without KU, eReaderIQ and patience are your friends! And yes, I pay a small amount to eReaderIQ through Patreon each month, since I value the website so much, so that's kind of like a subscription for me too
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