That's the trick: they can't make single cores faster so they just throw more cores at the problem and call it a day. Obviously that doesn't work but who cares? It looks good in benchmarks.
Thats why they should sell cpus that sacrifice security for speed. I'll take a cpu thats vulnerable to spectre/meltdown if its 20% faster.
You mean slower
Are you sure that they sacrifice speed for security? It's not obvious to me. Hardware fixes are supposed to be fast. That 20% slowdown comes from software implementation (and you can actually disable it).
I wasn't aware that the fixes for spectre and meltdown had no impact on performance.