Zoom Video Communications' (ZM 1.57%) stock is trading at less than $150 today and has a market capitalization of $22 billion. It therefore may be difficult for investors to wrap their heads around the fact that there was a point just a few years ago when the stock's market capitalization was greater than $150 billion and its stock price was closing in on $600.

This begs the question: With shares down so far from their high, is it finally time for investors to buy the tech stock? Or is this a classic value trap?

The bull case

One reason to be bullish on Zoom stock is its lucrative business model. For instance, the company generated free cash flow of $336 million in Q2 alone -- and that was on revenue of $1.14 billion. This means the company's free cash flow for its second quarter equaled 30.6% of revenue.

Adding to the bull case, Zoom's impressive ability to generate cash flow has helped it build a war chest of cash. The company now has $6 billion in cash, cash equivalents, and marketable securities.

Finally, investors are likely pleased with Zoom's recent customer trends. Enterprise customers rose 6.9% year over year in Q2 to more than 218,000. Further, customers contributing more than $100,000 in trailing-12-month revenue increased about 18% year over year to 3,672.

These are all encouraging facts. But the bear case, unfortunately, may outweigh the bull case.

The bear case

The company's slow revenue growth is key to the case against Zoom stock. Second-quarter revenue rose just 3.6% year over year.

Yes, Zoom is still coming down from a period of elevated interest in its product. COVID-19 lockdowns meant virtual collaboration was essential and video-based collaboration was often a replacement for communication that used to occur in person.

But investors shouldn't excuse Zoom's slow growth just because it's coming off of a period of heightened demand. After all, another factor playing into Zoom's slow top-line growth may be increasing competition.

There are many alternatives to Zoom, including products that are often bundled into services offered by the world's biggest tech giants, like Microsoft and Alphabet. Until Zoom demonstrates more rapid revenue growth, the stock may remain in the penalty box.

Even though Zoom's slow top-line growth is a bear case in and of itself, it's also evidence of a deeper problem: It's not clear that Zoom has a sustainable competitive advantage or, as Warren Buffett would say, a "moat." Competition could eat Zoom's lunch.

Overall, the stock may actually deserve its increasingly cheap valuation. Operating in a rapidly changing and highly competitive space, Zoom could prove to be a poor long-term investment -- even from its "cheap" price today.

Sure, Zoom could prove the bears wrong and demonstrate a strong competitive advantage. Fortunately, investors who are skeptical about the stock don't have to bet against it. They can simply take their money elsewhere, to a more predictable investment.

Despite Zoom stock's big fall from its all-time high, the shares look more like a value trap than an attractive investment.