James’ analysis found multiple sets were associated with a 40 percent greater hypertrophy response compared to single-set training.

Nonetheless.

According to Brad Schoenfeld, 2:

While this paper provided solid evidence in favor of increased training volumes, the analysis had some flaws. For one thing, James only looked at sets per muscle per workout; the weekly volume per muscle group could be a more important marker in determining the hypertrophic response. Furthermore, only 8 studies met James' criteria at the time, and only three of these used direct site-specific measures of muscle growth.

As a result, James and Brad enlisted the help of Dan Ogborn and decided to conduct a follow-up meta-analysis to determine the effects of weekly sets per muscle group on muscle mass changes. 3

They looked for studies that directly compared high and low training volumes for hypertrophy.

To begin, they looked at the effects of volume within each study and discovered that higher volumes were linked to a 3.9 percent higher average increase in muscle mass than lower volumes.

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The data was then divided into two groups:

 

The lower volume condition resulted in a gain of 5.8%, while the higher volume condition resulted in an increase of 8.2%.

 

 

Finally, they divided the studies into three categories:

 

Between volume and hypertrophy, there was a strong dose-response relationship.

 

Utilization

Low-volume workouts do help you gain muscle. A benefit of 5.4 percent was achieved by doing less than 5 weekly sets per muscle. So, if you have a busy life and can't devote hours to the gym, you can rest assured that lower intensity exercise will suffice.

If you want to maximize muscle development, higher volume approaches (minimum of 10 weekly sets per muscle) seem to be easier. The studies with higher volume (10+ sets) showed twice the gains as those with less than 5 weekly sets per muscle (9.8 percent vs 5.4 percent ).
It's not black and white: you can alternate between cycles of high intensity and low volume training. For example, 4-6 weeks of increasing volume followed by 2-3 weeks of decreasing volume.

“Volume Threshold”: Everyone has their own volume threshold; you can do enough to advance, but not so much that you risk injury or burnout. Over time, increase your volume'capacity.
The more advanced you get, the more volume you'll need to keep generating progress.