It won't for the foreseeable future. Not for technical reasons; it's just that other languages are usually not handled correctly because most companies think they can just use the exact same approach as in English and they're done.
Until they realise that non-English native speakers also use English words and abbreviations to some degree, both in IT-related contexts but also in everyday life. Now it doesn't just need to handle that one language but also English with an accent. If they're lucky it'll work reasonably well in most cases despite variations depending on the region.
Right now even keyboard completion suggestions struggle with mixing languages and become completely useless in some cases. As English words may be mixed in at any location (and in wildly different frequencies depending on the user) the software now has to guess the language for every single word. The results are not great.
> they say quality of Google searches have been declining, nevertheless we had a pretty good run for the past 20 years or so
As long as Google continues with blunders like showing wrong pictures of people in infoboxes they'll keep failing hard. Their amazing AI shows wrong pictures for serial killers, rape victims and more, which already led to consequences for those people. What makes it much worse is that when someone complains about such a case Google will just replace that picture with another wrong portrait - if they react at all. It would be helpful if those big tech companies would for once trust in human intelligence instead of throwing larger models at the problem.