No, because there are too many potential lines of communication as the team size increases. Let me explain:
The Scrum Guide says that the ideal Scrum team size is between 3 and 9 members. Here’s why: think of a team of two people, you and me. I can communicate with you, you can communicate with me. Pretty straight forward, right? Now let’s introduce another person - we’ll call her Kate. Immediately, there are more lines of communication: you can communicate with Kate and I at the same time, or just me or just Kate. Same for me and same for Kate. Now let’s add another person, Anand. We’ve introduced many more potential lines of communication now. Anand can communicate with me…or with me and Kate…or with me and Kate and you…
See where I am going with this? Potential lines of communication and therefore potential for miscommunication increases dramatically as team size goes up like so:
This is why the Scrum Guide recommends that Scrum teams be kept between 3 and 9 people.
But can I give you some personal advice? When I think of the very best, most productive Scrum teams I’ve ever worked with, they were almost always 5 - 6 people. In other words, they were in the middle of the recommended range, not at the top. This will especially be true for a team where most members are relatively new to Scrum. I have been a ScrumMaster for a team of nine people who were all doing Scrum for the first time and I think that might be a little what it is like to teach preschool. The chaos factor was very high because no one knew what they were doing. In cases like that, a team of six people will often out-work a team of nine, just because there are fewer potential lines of communication and therefore, less confusion.
So what do you do if you have a project that is clearly going to require more than nine people? You will divide that group into multiple Scrum teams (of ideally 5 - 6 people) and use a scaling model to coordinate the teams. There are many popular scaling models out there and, as with everything, I recommend you do your research and investigate at least three before you choose one. However, whichever model you choose, you will get a much better result by scaling Scrum with 4 teams of 5 people each than you ever will with a giant team of 20 people.