Like many large corporations, an employee's experience working for Amazon likely depends a great deal on their status within the company.
Amazon is an incredibly successful company with vast resources. As a result, those who work in their corporate offices enjoy the many perks associated with working for a tech giant, and employee satisfaction surveys suggest that the corporate employees are very happy in their positions. According to their website, Forbes ranked Amazon second on the 2020 list of best companies to work for globally. Forbes is a respected authority in the business world, and its rankings are considered significant.
Conversely, a number of exposés from lower-level Amazon employees have detailed the incredibly difficult conditions in their fulfillment centers, calling them grueling and inhumane. The extremely high rate of turnover in these positions suggests an equally staggering rate of employee burnout and dissatisfaction, lending credence to these assertions. A June 2021 New York Times report found that Amazon effectively replaces its entire warehouse workforce every eight months or so, noting that some executives fear they may eventually "run out" of workers.
In recent years, Amazon's advertising has made a very clear attempt to counteract this narrative by showing improved conditions for the workers in their warehouse environment. Whether this change feels as evident to those within the company is harder to say.
This answer assumes that the "best" place to work can be measured by an employee's relative well-being and happiness on the job, but there are also people out there who make this assessment using other metrics. For some employees, the "best" job will always be the one with the highest compensation, regardless of what the workday is like. For others, the best job might be the one with the schedule that best suits their needs outside the workplace. Others still might feel that the best place to work is determined less by their own experience, but by their ideology—in that case, the best job might be the job that aligns most closely with the employee's personal values.