If you're going to be bothered by details like slide rules and no cell phones, perhaps you shouldn't read SF. It's like complaining about a 70s novel picturing future appliances in avocado and harvest gold.
The stories weren't
about those details and today's SF will get just as many details wrong when we look back decades later.
Besides it's in the future, how do you know interstellar space travel won't require slide rules?