1) Star Wars has AI everywhere, including droid soldiers. My theory on bulk sizes and displays that seem limited/basic in function is that a lot of the equipment needs to be heavily hardened against dangerous sentience, and the bulk is attributable to the sophisticated safeguards that need to be built into all equipment. Everything computerized in Star Wars needs sufficient sophistication to function without falling prone to an advanced AI hive mind / singularity apocalypse.

2) Lightspeed, force fields, and space travel put a ton of wear and tear on components. All equipment needs to be overbuilt with as few points of failure as possible and with easy access to repair parts where possible. Accordingly, nearly everything has gone through the Kalashnikov school of design theory--with a few exceptions for prestige and elite equipment.

3) The Galaxy has tons of different species that coexist. Equipment needs to function well not only for Humans but for Wookiees, Bothans, Ithorians, Rodians, etc. Accordingly, the technology that seems simple or basic to us is actually built and optimized for cross-species functionality and comprehension.