The short answer is ONLY if students choose to compete. This should always be 100% their choice.

Collaboration promotes more learning than competition. This is true for students and adults. The reality is that there are many instances of competition that are implied throughout our classrooms systems in TK-5 education and beyond. For my purposes today we will focus on our youngest learners in grades TK-5. We have to remember that while many of our students like school for a variety of reasons they are still required to be there. If we require them to compete with one another overtly or otherwise we run the significant risk of diminishing their agency, the belief in themselves as mathematicians, and their love for learning. I don’t believe there is a single teacher whose goal it is to do this. We all want our students to thrive in our classrooms.
If we truly want our students to thrive we have to regularly reflect on how our chosen practices effect our students. We should pay particular attention to how our practices effect the least vocal, marginalized, and average students. Often times we hold up certain practices because we focus on the excitement of a few kids while not recognizing the reticence of many in the classroom. Continuous reflection and curiosity is essential as an educator.
A great example of this are the charts we see in many elementary classrooms that track progress for such things as math facts acquisition, number of books read, or other whole class record keeping that is public. These charts are a form of passive competition and the students are not getting to choose whether or not they compete. Imagine how the 5 students with the least stars/stickers on the chart feel looking at this public display of their performance. Does it inspire them to work harder or does it seem like a reinforcement of their public or self-perceived lack of ability? I would argue it is the latter. These charts should never be public. Take them down. They are not having the effect for our most struggling students that you would hope.
Timed math fact tests are another example. The general consensus among math educators is that these tests that hopefully WERE so prevalent in our classrooms a decade or more ago are bad for student motivation, create math anxiety, and do not provide us the insight into student learning that we think they do. But is there possibly a place for these tests. I might argue yes. If students are only competing against their own best times, if it is never whole class or required, and if students get to choose when and if they compete. This could be a “may do” for some students who express a desire. There are some students that enjoy pushing themselves in this way but they should be the one choosing to participate. The key is to be flexible within your classroom, be curious about your students and what they like and don’t like, and offer them choice.
Remember as adults we get choose if we compete, with the exception of public displays of state test data. Do any of us like it when this happens? As an example, we aren’t all required to play on an adult league sports team regardless of interest or ability. That would be insane. Competition is fun when we participate because we choose to compete. Let students choose! Reflect on your practices this summer and how you can utilize competition in your classroom for those who want to compete and eliminate it for those that don’t. It should be 100% student choice on a day to day basis.
Have a great summer! Keep being curious and keep learning!