That's true enough regarding Microsoft, but not all the other companies I listed let alone the many others that we could find*. However, when you say that nothing is up now, people will generally be considering the values now rather than the ones at a carefully chosen time in the past, fresh off Microsoft's wasting lots of money trying to copy Apple's portable devices and failing miserably. I agree with you about most of the predictions about Microsoft, because they're very embedded into the AI bubble and cloud will probably keep being profitable but won't grow infinitely. Investors really need to learn that nothing can grow infinitely and very little will come close. That is not the same as what you said.
Let's consider eBay. What could be more .com-like than that? It's just a website, a startup at the time, no un-duplicatable software, and it follows the .com pattern very well. It peaks in March of 2000 and then falls like a stone for several months just like everything else. How long until it beats mattress money? A little less than four years. How long until it was at 5% annual return all the way back to buying at the peak? Six months after that. It didn't grow massively using your arbitrary 15-year period, sticking around 5% annual return, but in the last decade, it has grown quite a lot faster. So if your definition doesn't work with that, the problem is much bigger than the now versus a decade ago problem.
In addition to all the companies that have continued to do well after that bubble, there are many others who were bought by someone else who has. They aren't being considered because it's impossible to tell how well the buyer would have done without them, but it happens. Bubbles end up losing and gaining people lots of money, but there sometimes is value under them, none of which proves that there's value under this one.
* To find the companies I listed, the primary challenge was naming tech companies that existed in the late 1990s and still existed today. Once I came up with a name, the chances were pretty good that they would fit the "up" pattern. There were some failures; my test of Cisco didn't work out well, but the bigger problem was naming companies that weren't publicly traded until after the bubble ended.