I fully agree. The challenge is, some will want to use the latest languages and technologies because they want to learn it (personal development, meaning: the next job). Sometimes the "new thing" can be limited to (non-critical) testing and utilities. But having many languages and technologies just increases the friction, complicates things, and prevents refactoring. Even mixing just scripts with regular languages is a problem; calling one language from another is similar. The same with unnecessary remote APIs. Less technologies is often better, even if the technologies are not the best (eg. using PostgreSQL for features like fulltext search, event processing, etc.)
This is a bit related to external dependencies vs build yourself (AKA reinvent the wheel). Quite often the external library, long term, causes more issues than building it yourself (assuming you _can_ build a competent implementation).