keep in mind though that size of the organization/team/... matters greatly. I have been involved with tens of projects over the course of my career (3 decades) and have encountered numerous scenarios where the choice of languages/technologies/... is already made, company-wide. I have seen this especially in companies that do a lot of contracting work. If apps are built say on top of springboot services and angular front-ends and we have 200 developers that specifically learned and know those technologies (along with myriad of internal libraries etc built on top of those technologies) swapping people between the projects becomes a non-event (or even adding few bodies to meet deliverables).