definitely yes.
Even sandy bridge was a good boost from Q6600, since then we have had 8 gens of core series chips with 3-10% IPC boost on every tick, cache speed improvements, new cpu instructions, and clock speed improvements, not to mention transition from DDR3 to DDR4, as the chipset is part of the package.
If you upgrading every single gen then yeah it seems bad, but its far better to at least wait 3-4 years between every upgrade, and then you will get decent performance improvements, I went from a 4670k to a 8600k and that was definitely noticeable, never mind from a Q6600 to a 9900k.
A Q6600 e.g. has no PCID, NVPCID, AES, AVX, no on board ram controller, and no onboard voltage circuitry. On a technical level its a long way behind the latest core chips. It also doesnt have HTT, which many are a fan off