Coopetition or co-opetition is short for cooperative competition.
Ela from Elamoore Natural Soaps should be my arch-rival, but we have been working together at markets for 10 years.
Ela is a full-time soap maker, I am a farmer who makes soap. She has a huge range of beautiful naturally scented soaps, I have five main types of goatsmilk soaps.
Co-operation
Ten years ago, I used to help her finish her stall set up at the Foreshore Markets in Busselton, as it took me under a minute to pull out my 2 trays of soaps.
Three years ago I invited her to join the co-op I founded at Origins Market in Busselton to improve the customer offering.

Before Origins opened, Ela had applied to take her own stall there, but like me, the opening hours didn't suit her business at that time, but being part of the co-op did.
Competition

Ela now has her own stall at Origins, but we still actively help each other in our businesses.
She helps me with bulk purchases of supplies and wholesale information, as she makes so much more soap than me.
I will be forever grateful that last year she told me about a global shortage of Cocoa Butter which meant I was able to secure some before everywhere was sold out. Ela uses Cocoa Butter in many of her soap recipes, and I use it in all my natural beeswax balms.
Ela brings customers to my stall if they are looking for goats milk soap, liquid soaps and essential oil blends, I take customers to Ela's stall if they are looking for pretty soaps, particular scents, laundry bars and pure essential oils.
I have never been particularly competitive, (except maybe at Scrabble, Wordle and Trivial Pursuit) and much prefer the values of co-operation as laid out by thisvsthat
This summary of coopetition from Investopedia resonates with me.
"The aim of coopetition is to move the market from a zero-sum game, where a single winner takes all, to an environment in which the end result benefits the whole and makes everyone more profitable."
There is a fascinating summary of co-operation v competition in Psychology Today based on the economic game the "Prisoners' Dilemma" It basically boils down to live and let live, or treat others how you would like to be treated, or a rising tide lifts all ships. They found that "even when the position of the other player was just a little more competitive than expected, it led people to adjust their own position on the next round, making themselves more competitive.."
You can play a little game on this site that proves how small changes in greed, trust, mistakes, and miscommunication can have huge implications in how successful you will be.
According to Wikipedia
"Coopetition is a portmanteau of cooperation and competition. Basic principles of co-opetitive structures have been described in game theory, a scientific field that received more attention with the book Theory of Games and Economic Behavior in 1944 and the works of John Forbes Nash on non-cooperative games. Coopetition occurs both at inter-organizational or intra-organizational levels. The concept and term coopetition and its variants have been re-coined several times in history and appeared as early as 1913"
In the Harvard Business Review
“Co-opetition”—cooperating with a competitor to achieve a common goal or get ahead—has been gaining traction for three decades. Yet many companies are uncomfortable with the concept and bypass the promising opportunities it presents. In this article two professors who helped introduce the approach offer a framework for deciding whether to team up with a rival.."
And the last word on the reasons why people don't embrace coopetition
Co-opetition challenges the traditional notion of competition by fostering strategic alliances that allow companies to leverage each other's strengths while maintaining their competitive edge. Despite its potential, many companies dismiss the concept of co-opetition, focusing too intently on the competitive elements rather than embracing the broader scope of collaboration, and therefore failing to tap into the extensive opportunities that partnering could offer. This reluctance generally stems from fixating on the small overlap where competition occurs.