"Not on streaming" is not the same thing as "Not available on a subscription streaming service". There was a time, not so long ago, that we all paid a rental fee to watch our programming.
Almost everything is still rentable/purchasable in digital form. Here's
Mr Robot for $25. There are 45 episodes so that works out to $.56/episode. Shoot the locks off your wallets.
And physical media is still available. And also has the advantage of being something you can sell once you're done with it.
Here's Mr Robot for $45.
End
Sorry, I am trying save money and decrease my subscriptions as well. I am not cold purchasing shows I've never seen for $25-45. Yes, I get that I can buy and rent most things on Amazon or buy the discs. I can also wait in line at the library for the 1 copy of the show my library service has.
Most of my post was playful poking, but certainly you can understand the frustration of having multiple streaming services and STILL having to rent/buy or get from the library a surprisingly big portion of stuff people want to watch. It's a pretty known show, so I was mildly surprised one of them doesn't own it and have it on their service. Shows like Faulty Towers I expect to have more issues finding.
I'm
kinda teasing too, but also a bit serious.
Paying for a monthly streaming service is just another way of renting. Sure it's an "all I can watch" version of it, but you still don't own anything once your month is done. The advantage is that you can watch an episode or two of a show and bail if you don't like it. But it's still sunk cost and you paid something for it in both dollars and time. Things still break down to a "cost per watch" amount.
I would advocate checking out the show from the library (if only libraries had more Blu-Rays!

) if only just to check something out. Unfortunately libraries will eventually/soon run into a lot of their movies falling victim to
disc rot.
To your point, is it surprising that Mr. Robot isn't available to stream anywhere? Yes it is. It was at one time, I know, because I watched it on Hulu. The licensing for all this stuff must be a weird thing. But not every buffet is going to have every menu item available at all times, I guess.
TLDR - Mr. Robot is worth watching no matter how you need to get to it.