And nothing big has happened despite all the risks and problems that came up with it. People keep chasing speed and convenience, because most things don’t even last long enough to ever see a problem.
A number of these supply chain compromises had incredibly high stakes and were seemingly only noticed before paying off by lucky coincidence.
The fun part is, there have been a lot of non-misses! Like a lot! A ton of data have been exfiltrated, a lot of attacks, and etc. In the end... it just didn't matter.
Your analogy isn't really apt either. My argument is closer to "given in the past decade+, nothing of worth has been harmed, should we require airbags and seatbelts for everything?". Obviously in some extreme mission critical systems you should be much smarter. But in 99% cases it doesn't matter.
By now, getting a car without airbags would probably be more costly if possible, and the seatbelt takes 2s every time you're in a car, which is not nothing but is still very little. In comparison, analyzing all the dependencies of a software project, vetting them individually or having less of them can require days of efforts with a huge cost.
We all want as much security as possible until there's an actual cost to be paid, it's a tradeoff like everything else.