One of the things I've been telling my team while developing our platform is that we have to build a product that was so good that people would want to steal it

One of the things I've been telling my team while developing our platform is that we have to build a product that was so good that people would want to steal it, and the current employees would harass us to keep access to if they moved on (it was an internal platform at the time). Your users are pulling your product out of your hands. Instead of seeing a problem here, I'd advise to set up meetings with them. Talk with them. Understand the problem they're trying to solve. What business reasons drive you not to have paid plans?