I worked in two different team in two different companies where a full rewrite of the core system was done in typescript.

The technology itself had few issues like compilation time and inability to run the application locally because of reasons.

The new systems were so complicated that everything ended in neverending bike shedding.

The people pushing for "everything to be written in typescript including other teams tooling (aka pulumi)" were very unflexible crowd.

The previous system had few issues that could be solved with database indices.

It's soul crushing to work on these type of places where technology is used for the sake of technology instead of bringing some business value.