I'd add that the status quo has done pretty well, and many of these exploits are fixed. It's also worth noting that a lot of the exploits in question may be known, but the people working on them couldn't theorize a practical exploit. How many web browser sandbox breaches have there been over the years? Far less than the CPU exploits in the past several years. The latter can have a much bigger impact though.
The biggest risk target seems to be shared servers, and you often don't know who you're sharing with, so is it worth trying? It seems to be usually, no... in a specific target, maybe.
Web browser sandboxes are broken all the time using conventional bugs.
Bad news, 1993 was 30 years ago. Maybe 50+ years ago at this point.
No, 1993 is about right. The mainframe guys were screaming their heads off as these dumbass, insecure, non-ECC x86 processors were eating up more and more computing--before that the mainframe guys kind of dismissed x86 as simply toys.
Nobody wants to be the first to take proper steps because they have to either:
1) Partition hardware properly so that users are genuinely isolated. This costs silicon area that nobody wants to pay for.
2) Stop all the speculative bullshit. This throws performance into rewind and will put chip performance back a decade or two that nobody wants to pay for.
Until people are willing to value security enough to put real money behind it, this will continue ad nauseam.