That's incredibly unfair. Scifi is a very broad category. Some of the best imagines just a small change to the world and watches how people live around it. Some is imaginative flights of fantasy, some is realistic futurism. And yes some is the presentation of technological ideas using the story as a simple vehicle.

Lem is great, as are a variety of other eastern authors, but they're not head and shoulders above their western counterparts nor is the genre lacking in literary skill in the west.

See for examples - Phillip K Dick, Iain M Banks, Daniel Keyes, Frank Herbert and many others.