At a previous company, the tech influencers believed in the archaic "do everything in the database." While we were technically using the .Net stack, we weren't allowed to do any actual business logic in C#. Instead it had to all be done in MS-SQL procedures (or at least at much as possible with very little CLR glue).
Similarly at my current company, we had a product were the initial devs wanted to jump on the RXJS and Socket.io bandwagons. The only problem was the rest of the company was using standard REST endpoints and promises to do the same thing, so any new devs who joined that team suddenly had massive cognitive overhead they had to overcome. Any changes to the codebase we're done by people who only half understood what they were doing, and so the complexity compounded. Thankfully, I was given the chance to rewrite the whole codebase to match what our other products looked like, so now the code is much more sane to work with.