They are not. They are based on leaking microarchitectural state such as the contents of the store buffer, while spectrev1 is based on leaks from the branch predictor.
The difference is that the contents of e.g. the store buffer are short-lived, while branch prediction is by design learning behavior of the program for long term use.
It's not a coincidence that Spectre v1 affected all processors and not just Intel x86. Also Spectre v1 still has no widely-deployed hardware mitigation, while for all other vulnerabilities the processor could be patched to add a "flush the leaked state" instruction with a microcode update.
The difference is that the contents of e.g. the store buffer are short-lived, while branch prediction is by design learning behavior of the program for long term use.
It's not a coincidence that Spectre v1 affected all processors and not just Intel x86. Also Spectre v1 still has no widely-deployed hardware mitigation, while for all other vulnerabilities the processor could be patched to add a "flush the leaked state" instruction with a microcode update.