We definitely have the capacity to build spacecraft to the quality standards of Voyager. Samsung would probably be willing to support your 2023 era Galaxy cell phone, if you're willing to spend $800m on it.
I am lucky if my cell phone lasts more than a year. That's definitely you, not the phone. Most people's phones last longer. Partially evidenced by folks complaining about updates stopping after a few years.
I have a feeling that even if today's hardware manages to last 50 years, all knowledge of how to talk to it will be long lost. I am sure some of the code/firmware will be proprietary and then contractor will go out of business and that is that. Most of today's hardware isn't expected to last that long - and it wouldn't matter if much of it did. No one wants 50-year-old medical equipment unless it hasn't improved in 50 years. A 25-year-old computer isn't worth much to the average consumer. And some stuff will just be outdated: Do you really want to use one of the digital typewriters that combine a small-screen simple word processor with a typewriter?
Things that we build for longer-term science generally is built to a different standard than the stuff we use at home and has different constraints and different sorts of moving parts. Especially when considering extreme environments. And most of these are made by governments, universities, and other institutions that tend to have a long lifespan when compared to corporations. And when they aren't, we can make sure to make laws so others can use science research things even if the company closes.
Additionally: I think everyone expected Voyager to die long ago. It is akin to a fridge that happens to still be running 50 years later. A lucky accident.
This speaks more to the quality of engineering than lucky accidents.
NASA sets high bars because many of these projects have a single chance of working. They make decisions that maximize the chances that the equipment will function within mission parameters, and the result is often something that far exceeds the original mission. See: Mars helicopter.
In the consumer space, an old fridge continuing to operate isn’t chance either. This truly is a case of “they don’t make them like they used to”.
Edit: I’m a bit surprised this is controversial. Curious why people feel this is wrong.
Also something about Cuba. I think my point is that we're a bit too cavalier with used electronics these days. The embodied energy and materials are huge, and we just... throw them out, in many cases. I'd like us to get used to repurposing these resources before scarcity forces us to. Really squeezing every bit of use out of them that we can. Bonus: because it's not the Hot New Thing Someone Is Trying To Sell You, you'll likely be less subject to the Hot New Trend Of Actually Being The Product.
And, for what it's worth: an original Apple I just sold for almost $450k at auction. Someone wanted that.