This happened a few months ago. They changed the backend completely. You can also notice it’s much slower (say from 5 ms to 200 ms). But I don’t think it’s worse.
The translation built into Chrome regularly misinterprets Japanese as Chinese (despite this being objectively, trivially detectable for any significantly long string based just on the codepoints) and offers no way to correct it.
This is a new regression!
It is. There are cases where simple words or common expressions in very mainstream languages (French, German, English) just aren't translated at all or translated ridiculously badly.