There appears to be something of a software engineering crisis in academia.
Imagine that you are a graduate student or a newly minted PHD who happens to be pretty good at practical software engineering: You can leave academia for FAANG and a solid six figure income, or you can stay struggling, poorly paid, unable to get tenure in academia. In some groups software engineers are treated as glorified typists, too valuable enabling other people's work to be a principle researcher themselves. I've heard from a number of people that they avoid hiding their programming skills to avoid that trap.
This has many consequences beyond the obvious direct ones like papers with unusable implementations.
Academic work is often valuable even when it isn't practically useful but in many cases where academics are /trying/ to do something practical they fail because their community lacks the engineering experience-- I've seen a fair number of papers presenting optimizations as useful engineering when in reality their approach only makes sense because of inefficient non-programmer tools make a weird set of primitives fast (e.g. using a matrix multiply in matlab where in C you'd simply write a loop). As a practitioner this is frustrating because it sometimes requires re-implementing the approach to realize that it was only 'fast' compared to a pants-on-head-foolish approach.
It also can create essentially fake results.
Many times the lack of software engineering is compensated for by mocking components out in ways that would give faithful results if the researcher understood everything, but the whole point of expirementation is that the researcher doesn't! This mocking is seldom disclosed in papers. For example, I've encountered multiple papers that claimed to implement some enhancement to Bitcoin and tested it in a test bed but in reality they just added sleep()s with appropriate times, guessed out of specious reasoning like "our function X should be 10x slower than a signature", and hardcoded constants (computed in mathmatica or sage) for their messages. ... not realizing that sleep() isn't the best analog for cpu busywork in a multithreaded program!
Another kind of fake result I've encountered which is even less directly a result of the software engineering shortage is in signal processing literature. While working on audio/video compression I found it common for algorithms to be presented without various constants and after reimplementing and asking the authors for their constants I found that they'd been cherrypicked for the ten images used in the paper, and that the whole approach doesn't actually work. This is a kind of ineptitude (or outright dishonesty) that would be much less common in a world where reviewers received a working and usable implementation in source form-- but that can't be expected in a world where qualified software engineering is not readily available to researchers.
I don't have any proposed solutions but I think it's important to acknowledge that it is a common and serious limitation to the usefulness and accuracy of contemporary research.