You're definitely smart enough to know a sweeping assessment of silicon valley based on a single, isolated sample is a mistake.
Since you are talented enough to get hired by a "big tech company" in silicon valley at the age of 19, then you're definitely talented enough to find tons of other work here. There is _TONS_ of fascinating and rewarding work being done here.
https://news.ycombinator.com/user?id=whoishiring
https://news.ycombinator.com/submitted?id=whoishiring
https://news.ycombinator.com/item?id=11012044
Before you go hopping into a new job, realize that nearly every task, paid or personal, can occasionally feel like an unrewarding slog. Heck, even contributing to fun stuff, like open source or HN, can occasionally feel like a frustrating struggle, annoying hassle, pointless toil, or thankless grind. When those lackluster moments happen and you can take a short break, just divert your attention to something interesting for a while until they pass.
Also before you go hopping into a new job, have you been rewarding yourself with spending free time doing interesting side projects?
Is there any technical itch that you've always wanted to computationally scratch?
If you pick the right itch, you may end up creating your own startup. As John Belushi once said, "If you don't like the news, go out and make some of your own." The same applies for jobs.
Of course, having a full time engineering job will keep the lights on so to speak, and it gives you the opportunity to spend your free time experimenting on side projects you love. Lastly, don't forget that the Bay Area has _TONS_ of different types of user groups, maker sites, and enthusiast clubs with regular meet-ups. There are also plenty of conferences and professional groups here. All of these groups, places, and events are a humongous asset to the curious and are thoroughly enjoyable.
Silicon Valley is what you make of it.