Let's count all the reasons not to leave:
1) If you don't have an amazing idea now, leaving won't make it easier. If anything it will be worse since you won't be constantly exposed to real-life problems.
2) Building great product is about a lot more than ideas. It's about execution, timing, scaling and a ton of luck.
3) After only two years at Google you're probably an L3 or L4 engineer. You have much to learn. Seriously. It probably took you a year to become productive so you've only scratched the surface. Go find a senior mentor and get them to talk about their journey. You'll be surprised.
4) Startups are hard. Don't believe the hype. Your startup will fail you. Even if the startup succeeds, you personally are unlikely to hit a payday. Remember the Golden Rule: Those who have the gold make the rules. The most likely outcome from any startup is that it fails. The second most likely outcome is that it fizzles and gets bought. Your equity would turn into a diluted options over 4 years.
5) In another 3 years at Google you'll save so much money that you'll have an entirely different set of financial options
6) Your long term career impact and financial success will actually be better off if you find a way to apply your ideas and passions within Google.
7) You are currently surrounded by some of the smartest software people in the world working on some of the hardest problems.
8) Look for a transfer to one of Google's SE Asian offices. Lots of interesting projects there.
To be blunt, it sounds like you're finding out that working as a software engineer is, well, work. It is. That doesn't mean you can't find your passion in what you do.
Buy yourself your own computer and work on your dreams at home while receiving the engineering and execution experience of your lifetime. Actively seek to learn more about your craft from a company that is still writing the book on this. Take advantage of internal instruction opportunities to expand your skillset (where else will you get paid to learn about ML from some of the best). Once you've earned your stripes at Google you'll be able to work anywhere on a just about anything. You'll also find that you actually understand the realities of product development and software engineering in ways you do not today.
I started working at Microsoft in the late 80s. I'm now at Google as a PM. I've done a bunch of startups and consulting along the way. My career has spanned over 30 years and there's no doubt in my mind that it was the time at Microsoft that gave me experience, skills and opportunities I would never have had elsewhere.
If your heart is set on the romance of startups, go find it. You'll learn a lot there too. Just don't do it because you're bored of work.
PM me if you want an extended version of this with Google insider specifics.