Alphabet (NASDAQ: GOOG) (NASDAQ: GOOGL) subsidiary Google recently announced plans to acquire Fitbit (NYSE: FIT) for $2.1 billion. The takeover would make Google the fourth-largest wrist-worn wearables maker in the world, but it still faces a tough uphill battle against market leaders like Apple (NASDAQ: AAPL). Data source: IDC. Chart by author. Google already owns Wear OS, but the smartwatch platform failed to gain enough developers and many of its hardware partners abandoned ship. It also acquired some of Fossil's smartwatch tech earlier this year. Google's purchase of Fitbit could pave the way for its long-rumored "Pixel Watch" to hit the market. However, analysts expect Fitbit's sales to decline 4% this year as it falls further behind companies like Apple, which generated "strong double-digit growth" in Apple Watch sales last quarter, according to CFO Luca Maestri. It's also unclear whether Google will replace Fitbit's OS with Wear OS or the other way around. Either way, Google could struggle to gain as many developers as Apple's WatchOS, and it still faces competition from other smartwatch makers like Samsung, which notably replaced Google's Wear OS with its own Tizen OS. In short, Google's big bet on Fitbit won't be its magic bullet for conquering the wearables market. Offer from The Motley Fool: The 10 best stocks to buy nowMotley Fool co-founders Tom and David Gardner have spent more than a decade beating the market. In fact, the newsletter they run, Motley Fool Stock Advisor, has quadrupled the S&P 500!* Tom and David just revealed their ten top stock picks for investors to buy right now. Click here to get access to the full list! *Stock Advisor returns as of June 1, 2019.Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool's board of directors. Leo Sun owns shares of Apple. The Motley Fool owns shares of and recommends Alphabet (A shares), Alphabet (C shares), Apple, and Fitbit and recommends the following options: long January 2020 $150 calls on Apple and short January 2020 $155 calls on Apple. The Motley Fool has a disclosure policy.Source