Warren Buffett is one of the richest people in the world, and he didn't get there by accident. Unlike other top billionaires, many of whom acquired their wealth through entrepreneurship, Buffett has made most of his money by buying shares and ownership of established companies through his company, Berkshire Hathaway.

Let's explore the reasons why two stocks in the Berkshire portfolio -- Amazon.com (AMZN -1.43%) and RH (RH -1.22%) -- could make you richer in 2021.

1. Amazon.com

Berkshire first bought stock in Amazon in 2019, and the stock has performed exceptionally well. Shares are up 71% so far in 2020. Amazon benefited from increased demand for stay-at-home shopping during the coronavirus pandemic, and it can deliver greater returns in 2021 by investing in high-margin business opportunities such as cloud computing and digital advertising.

Amazon deserves its large price-to-earnings multiple of 93 because of its spectacular growth rate. Net sales increased by 37% to $96.1 billion. And operating income soared by 96% to $6.2 billion -- boosted by strength in the high-margin Amazon Web Services segment, which alone represented over half of total operating income. 

Hands over piggy bank and dollar bills

Image source: Getty Images.

With the global cloud computing market projected to grow at a compound rate of 15% through 2027 as more businesses move to cloud storage, Amazon's AWS platform can help power long-term earnings growth. The company is also developing additional business opportunities such as digital advertising -- an opportunity projected to be worth $130 billion in 2021, according to estimates from research company GroupM. 

Right now, Amazon boasts a 10% market share in digital advertising, compared to Facebook's 24% and Google's 30%. But Amazon is well-positioned for success in this market because of its large user base of up to 300 million and the customer data these users generate. To add icing to the cake, Amazon's Prime service (which boasts over 112 million subscribers) features a video streaming platform that allows advertisers to reach audiences alongside high-quality content. 

2. RH

Buffett is no stranger to the furniture business, buying an ownership stake in Nebraska Furniture Mart for $55.35 million in 1983. RH, formerly known as Restoration Hardware, makes another compelling addition to Berkshire's furniture stock portfolio because of its impressive growth rate and the positive dynamics in the housing market. RH can deliver continued value to investors by boosting its profit margin as it transitions to a more luxury-oriented business model. 

RH has bounced back from coronavirus-related store closures and supply chain disruptions, and now it's benefiting from a robust housing market as historically low mortgage rates drive homeownership and newbuild construction. 

Furniture for sale in a furniture store.

Image source: Getty Images.

In RH's third fiscal quarter, which ended Oct. 31, revenue increased 25% to $844 million while adjusted net income soared 154% to $166.5 million. The company enjoyed a dramatic improvement in its adjusted operating margin, which increased from 13% to 26.7%, as it establishes itself as a luxury brand that can command higher prices. Management also used the coronavirus pandemic as an opportunity to streamline the business by terminating or furloughing workers and temporarily cutting executive salaries in April. 

RH will likely experience continued success in 2021. While management hasn't provided concrete guidance, the housing market remains strong, and CEO Gary Friedman expects "double-digit revenue growth and expanding operating margins" in the future, according to the company's third-quarter earnings call. 

Investing like the Oracle of Omaha 

Warren Buffett has a track record of betting on quality companies. So when he backs a particular stock, it can pay to find out why. Amazon and RH are both great stocks to invest in for 2021 and beyond because of the favorable macroeconomic environment and their company-specific growth drivers.