I completely agree, Blade Runner 2049 really was true sci-fi and developed the ideas and universe of the original in quite clever and interesting ways. I especially liked the ambiguity around Niander Wallace — he was nominally a villain, but in a strange way was trying to better the lot of the replicants, eliminating the major justification for denying them equal status to natural humans.
It is a shame that pure sci-fi has suffered such a decline, and been displaced by futuristic action/fantasy/horror. I watched Altered States for the first time in decades a few weeks back (picked it up cruising the Amazon cheap DVD section). Even with all the dated effects and tropes — the early-80s interpretation of the hallucinations was especially funny — it was worthwhile just to watch real sci-fi again.