Would you have put Google and Facebook in this group when they weren't profitable? You are missing something - many companies have great long term economics even if they are losing money right now. Slack (if still independent) could easily be profitable - they just have to spend less growth (ie, largely they could cut their sales and marketing dramatically, along with other items). Snapchat the same, Pinterest the same. Some of the others I believe you might by and large correct. The general statement that lots of companies are giving away dollar bills for $0.80 isn't right.

Why Dropbox? Did something change?

I haven't paid attention for many years, but at one point is was an extremely profitable company.

Are the fake-meat companies tech companies? I thought they are more like contract manufacturers, brewers, or other industrial foodstuffs.

No doubts on the access to cheap debt, though.

About half the companies you mentioned are cash-flow positive, so their economics work, they just have accounting for depreciation and other lines on their balance sheet. They are default alive companies using accounting practices to avoid taxes, but they have more money coming in than going out