The JavaScript Number type is implemented as an IEEE 754 double and as such any integer between -253 and 253 are represented without loss of precision. I can’t say I’ve ever missed explicitly declaring a value as an integer in JS. It’s dynamically typed anyways. There’s the languages people complain about and the ones nobody uses.
And then JSON doesn’t restrict numbers to any range or precision; and at least when I deal with JSON values, I feel the need to represent them as a BigDecimal or similar arbitrary precision type to ensure I am not losing information.