HashWithIndifferentAccess was added because back in the day symbols were immortal, hence could not be used for request parameters.

It no longer make sense today, and any new use of it is a smell.

Agreed. However had it should also be mentioned that this originated from rails.

Many bad things originate from the rails ecosystem. (Arguably some good too, but I am very pessimistic ever since shopify's recent powermove and DHH side-line commenting off-the-fence while being on shopify's board.)