Until they figure out how to make a drive not fall off he face of cliff once the cache is exhausted it doesn't really matter unless all you're moving around are small files.
When moving the touted gigs of data around usually those high speed die after 10-15 seconds when the drive runs out of cache. I can avg 1,.5GB/s between 2 internal drives that are Gen3 and Gen4. I can speed test them at 3-6GB/s but, in real copies they don't hit those speeds. There's a lot of bottlenecks to consider in the path for the data to run into. Even using the latest HW / CPU / etc.
Ideally using a PCI card to bypass the issues with native M2 slots and allow direct communication between drives would get rid of most of the hurdles when it comes to hitting claimed speeds in a sustained speed use. The problem then becomes do you use a switch or bifurcation. If it's Intel you need a switch and AMD it's bifurcation. Intel multi NVME cards get expensive ~$600 for a 4 drive card. AMD ~$100. Most of these cards though still use Gen3 slots / wiring.
https://www.amazon.com/PCIE-Adapter-4x32Gbps-Cooling-Windows/dp/B09XJV6J59 - $42 / 4 drive / bifurcation
https://www.amazon.com/dp/B0892VBP7P/ - $500+ / 4 drive / on board switching
The other issue is with the switching module slowing things down to Gen3 speeds or less. Getting into the higher end cards can get better results but, it's insane pricing. Better off building a AMD system for the same price and using the cheaper card.
Gen5 drives really won't matter unless you're doing a lot of data queries like a DB / SQL type of transaction that needs the higher bandwidth. Sure 14GB/s sounds nice but, in reality it's mostly only used during boot of the system. Sure my Gen4 drive allows me to install W11 in ~30seconds but, it doesn't really get touched for speed unless moving tons of files around. A game barely uses it and just loads into the GPU DDR directly with a small increase in RAM usage.
I see the biggest flurry of comments coming from PS5 owners adding M2's to their devices and I think Sony put a minimum speed of the drive at 5GB/s.
It might make sense for people using devices like high res photography if they're equipped with a USB-C port to connect an enclosure to for recording raw files to. Maybe feature movie footage being stored directly to an NVME Raid?