They were groundbreaking, foundational works that influenced everything came after them. The later works were often amplified takes on what came before; explicit attempts to out-do their ancestors.
(Sometimes this works, and sometimes it doesn't. You don't always improve things just by adding more...)
So, folks go back to the originals and wonder: "what's the fuss about? what was so groundbreaking about the hard-sci-fi-ish space marines and H.R. Giger visuals in Aliens? or the boring, soulless, pondrous killer in Friday the 13th? " The originals seem tame or quaint by comparison to what came after.
Know this: there is a whole world of enjoyment out there waiting for you should you ever decide to appreciate works of art in their appropriate historical contexts. Blade Runner has its faults and its charms and is by no means a perfect movie, but it is arguably the most visually influential movie in history or damn close to it.
Things are never entirely born from nowhere, but Blade Runner's now-cliched "neon cyberpunk dystopian future" look had never been really done before, certainly not on the big screen, and I'm honestly not sure if it's been done better since.
As far as discussing Blade Runner on its own merits, outside of any context... I understand why some think it's boring. It's slow and meditative. Deckard is a cipher. But this is by design. It works for me, mostly.
Of course, if you just want to skip all of that context business and focus on the latest/flashiest works in a particular genre... that's cool too. Literally nothing wrong with that. It's art. You can interact with it however you want. Don't let anybody tell you otherwise.