Edit: I mean, this is the company that gave us the 8 Fallacies of distributed computing, as they were 20yrs ago
They didn't. Not that any of it is important anyway. All 80s and early 90s networking tech was ridiculously broken, which should be obvious, since distributed systems field was just born at that time (first papers in like 1978). Things started to get useful only by the end of nineties. But by that time Sun's tech was nowhere near anything internet companies were doing. So later when things got to infrastructure Sun's engineering was really really behind, they had to start from scratch on anything that internet companies were learning and doing for many years. And this was very different time consuming knowledge, not something where someone could use their OS level expertise. Which also makes it very hard to compete with companies that are much farther ahead, especially with this silly "our tech is the greatest" attitude making it hard to even realize how far behind you actually were.