As Robert details in his answer here, "This is a a fully functional, launched site. It is not "in beta" as you've come to understand it the traditional software development model, or "in testing" or something that failed to "graduate"."
So while we certainly don't have to be enthusiastic about currently falling question per day numbers Stack Exchange won't shut us down for that. As Chenmunka points out there are plenty of sites with even worse question per day numbers.
Moreover, the relevant meta post defines closure criteria as follows (emphasis not mine):
If there's enough moderation for a public beta site to consistently remain free of spam, for flags to be cleared, and for our Be Nice policy to be upheld, your site will remain open.
That part of the site is alive and well. We have active community moderation by close voters and flaggers and even with moderator vacation those flags are handled pretty quickly. To be clear, I'm no member of the Stack Exchange Community Team, but I don't see any danger of us being shut down anytime soon.
Are we next in line to get a shiny graduation design, ditch the beta in the title and get elections, no we're not. But, we're not dying here either. So this is very much a place where people can spent effort in good questions and answers without the fear of them being deleted at anytime.
Hope we could contribute something towards it!
Well, we can. By asking good questions, providing good answers and promoting the site. Participate in meta like with this question to shape the site to be a better version of itself. If you know somebody who might be interested point them here. If you have a platform, share a good question from this site. If you've got another good idea, go for it.
