The speed AMD has raised caches & core-count lately is insane. When the max for mainstream CPUs was 8MB (and 4 cores) until only a few years ago. (Things seem to have stopped when quad-core launched, the Intel Q6600 was an amazing CPU at the time.)
I've been a computer enthusiast for over 20 years and didn't expect to see advancements to return like the good ol' days (Moore's law) to ever return. (I don't think Intel did either, halving their prices pre-launch is unprecidented!)
Do remember that part of how AMD can get so much L3 on there, is due to the chiplet design, which also adds a LOT of latency to ram accesses. Almost all of the time, it seems to be a net win though, and with the next generation it will only get better.
However, DDR4 memory now provides more bandwidth than the L4 could (although probably at a higher latency).
Though, perhaps 3D integration can stave that off for many more generations.