I know this is how people in the 80s and 90 imagined the future and a lot of concepts were probably too far fetched for them.
You also have to consider that TV executives were also considering this, and punting any ideas they thought wouldn't be accepted by a TV watching audience of the 80's/90's. Like the planned gay characters who were scrapped.
I mean, think about that, being gay in the future was too much for some television executives to accept, I really wouldn't be shocked if they gave thumbs down on lots of more esoteric and abstract episode concepts simply because they thought it would be too above the heads of a 90's TV audience.
And to be fair, they were probably right. The communicator seems less amazing now that we live in a world with cell phones, but back then a personal communications device that was on your person at all times seemed definitely in the realm of sci-fi. Now we all have a near-equivalent in our pockets, as well as it being general purpose computing device that can be used as a personal communicator and much more. Our communicator is also a primitive tricorder.
Some of the ideas they did let pass were either already accepted tech from the original series or were close to existing civilian or military hardware that was in it's infancy.
So a combination of "this was the extent of human imagination about these concepts back then" combined with "television executives are keenly aware of ideas the general public won't understand, and doesn't like confusing audiences, and thus will cut any content they deem too abstract or confusing" is what I think actually happened. One part actual limitation of imagination, one part purposeful limitation of imagination as to not to confuse the audience.
Which, honestly, is fair. Do you think sci-fi series like Rick & Morty would exist as they do without all previous sci-fi series laying down frameworks we understand for it to be based on? Human knowledge and ideas do build on themselves, and so, in a way, the TV executives are half-right that you can't overexpose an unexposed audience. You kind of have to slowly spoon feed them ideas over time.
Like, what if we tried sending Rick & Morty as a show back to the 1960's, and how many of the ideas would be entirely over the audiences heads? Simply because they didn't have 60 years of sci-fi media relating different iterations of these various ideas until "the multiverse" is just talked about like it is just a given thing that exists, and nobody questions it. At least a few would have trouble wrapping their minds around it, because while many of these ideas were pioneered in the Original Series, their lack of depth might leave audiences back then really confused about some of the ideas presented.