ראה תמיכה בדפדפנים בקישור הבא:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/finally#Browser_compatibility

will never *throw* the 'ex' (sorry)

exactly. While the feature is nice to whoever still has to use promises directly, using async/await code makes it a bit redundant, IMO.
A simple try/catch/finally around the await makes the code simpler in all aspects.

The code you offered will never through the 'ex' outside to the calling code.

.then(data => {console.log('success')})
.catch(ex => {console.log('failure')})
.then(() => {console.log('finally / always')})

When using async await try catch is the equivalent of promise.then and promise.catch.
promise.finally is the equivalent of try catch finally