I've been watching this for a long time now. While both questions and answers are growing, there's a somewhat faster increase in questions than answers, and over a period of a couple of years it can be quite alarming (and then there are occasional apparent rapid increases - "jumps" - in the level of questions that I have no good explanation for).
While the problem that the answer rate isn't keeping up is likely to have many sources (among other explanations see Why is our answer rate so low?), one source than we can do something about is that we are overly tolerant of poor quality and near duplicate questions. The biggest growth seems to be in that segment of poor and duplicate questions.
Duplicates can sometimes be hard to locate, even if you are confident you've seen one (it's usually worth a try, though because it makes the site much more useful when we do find them), but unclear/off-topic/ etc questions can often be spotted quickly and it takes very little effort to vote (or flag if you lack the voting privilege) to put them on hold.
I agree that there's a rapid growth of interest in data science and machine learning topics and that's certainly a part of the problem.
We have had a few new people answering a lot of questions recently -- that's great to see, but there's lots more questions that we can deal with.
I'd like to attract more people to answer, particularly in the areas of rapid growth though I am not quite sure how to do that. Bounties do seem to help a little to encourage budding answerers - and we've had a lot more bounties lately - but it's not going to be enough on its own.
All the curation activity that goes on -- people who to try to make the tags better, the people who quietly edit questions into good approximations of clarity and comprehensibility, the people who flag and vote to close and so on -- that all helps tremendously, and there are some people who contribute a great deal on that front. While that doesn't directly answer more questions, it keeps the site viable and useful and among other things makes it more attractive to answer questions, encouraging answerers to move from responding to one question to tackle more.