It's hard to put a date on it, but tech, and especially tech companies, stopped being "cool" not too long after 2010.
The problem is that the industry has matured. And not in a good way.
Tech used to be largely about discovery and invention and making computers work to make people's lives better. Over the last decade, there has been a very rapid shift to tech being about exploitation and monetization and all the bad things that come with human endeavor.
I don't blame tech people for this. There exists an underclass of people — vultures or grifters, for lack of a better description — who wander from hot thing to hot thing trying to make money as quickly and unscrupulously as possible. I think of them as a collective of shady real estate agents and shadier used car salesmen, who follow the trends from one industry to another in order to "get my share" and destroy that industry as a result.
In modern times, it happened to banking. It happened to real estate. It happened to tech. It's happening in crypto. It'll happen to VR soon. Probably space flight shortly after that.
Tech is not inherently bad. But it's been made bad by the number of people who are in it for the wrong reasons outnumbering the number of people who are in it for the right reasons.