Oh I don't either - I use a jailbroke Firestick (fully legal); I actually don't pay for any streaming service outside of basic cable-internet (while watching all of them).
I also rarely watch any show 'on launch' - many times I'm starting or watching shows weeks if not months after release. And by then we (you, me, everyone) has a better idea about what IS perhaps worth the time to see if I like it and what is "total trash." (heck even if I don't want to know and haven't bothered to read a single review about something, I still hear about it - lol)
If you already know you aren't going to sub-up to Amazon "just" to check out LOTR then that 'grace window' is to your benefit anyway and not something you need feel frustrated by (?). If you're having to 'wait anyway' then you'll just have a better idea if its worth checking out - whenever you decide its worth it to subscribe. IMO - Before a show goes live there's just too few 'reviewers' (legit or otherwise), or too little content they are judging (like the handpicked 20 minutes in this example) to really 'count on' anyone's take unless that person was already vetted by you; I agree, you can't "really trust" any of it.
And I also agree there's not a single show on air (today or in the past) - that by itself - would be 'good enough' for me to pay a streaming subscription for. I'd at least wait until a streaming service has 3-4-5+ shows I'm behind on before I'd go paying a monthly subscription long enough to catch up; and then bounce to the next service once I'm caught up on that one, etc. There ARE way too many (at least for all the tv I watch) shows for me to keep subscriptions on all of them active at once.
And I do hear you on trying to find a reviewer, any reviewer, who shares a similiar 'movie brain' to you - it is a struggle when you're on the fence about a show and whether to bother watching. Up until two years ago when I randomly stumbled upon a youtube streamer/reviewer who, over time, I realized DOES share that same "movie brain" with me - I would have said the same thing as I'd never read/watched a reviewer that did. And I certainly didn't put forth any time/effort to find that one; just stumbled on him (Chris Stuckmann is the reviewer/streamer in case anyone wonders or is looking for one who might be a good match. He definitely shares my movie brain on everything except our opinions on the Alien series =D; but hey no one is perfect ).