We may be in a bit of tech bubble right now, and it would suck if a lot of people lost their jobs (although firms are a lot smaller than they were in the last one), but there is barely any public money on the line these days.
Yes VC backed firms supposedly generate 21% of US GDP right now (although I find that number to be a tad suspicious), but we have to allow that a huge chunk of that number is for new-tech companies (someone at MIT invented a new type of concrete, or a robot), biotech (someone at Johns Hopkins invented an artificial heart), and other niche businesses where the goal is definitely not to be a unicorn, but to hit a definable market.
Certainly it would be sad to see some of these unicorns die, but as an overall percentage of where a lot of VC money goes (and I mean the whole world of VC, not just the SV VCs that are interested in the next billion dollar companies), they don't make up a huge percentage of the employment or income in this country.
We might be in a bubble and it might pop, but the assumption that it will hurt the economy like it did in 2000 needs to be backed up by a stricter line of thought than, "the last bubble did".