That should be more than enough for 90% of the cases.
Do we even have 1% of people complaining about PCIe 3.0 yet? Sure, we have NVMe drives maxing out 3.0x4 but does it really matter? While PCIe 3.0 NVMe has 5-10X lower latency and 6X as much bandwidth as SATA, games and applications only load 10-20% faster so 4.0x4 isn't going to be particularly helpful for everyday use until there is a paradigm shift in how software loads stuff.
Consumer-wise, it is still nice to see PCIe 4.0 get in the mainstream before IO becomes a legitimate concern for a meaningful number of people.