This show you don't need more RAM, but only you can tell if you need a faster machine. Depending on how you use your machine, the 10 GbE might make the biggest difference.
To be honest, I don't need more speed either.
I thought I'd get into some very basic video editing, but I ended up getting LumaFusion for M4 iPad Pro instead so I've done it on that, and it turns out I don't use it much anyway. For other stuff like OS navigation, surfing, various other apps, My M4 iPad Pro sometimes seems a touch faster than this M1 Mac mini, but the experience is actually pretty close speed-wise overall IMO. I'd guess if the M4 is a 9.5 for that stuff, the M1 is still an 8.5.
As for 10 GbE, my network is actually only Gigabit, but I've separated one Ethernet run from my modem which can be used to directly access the modem with my 1.5 Gbps cable internet service (which actually sees 1.9 Gbps at the modem). My current NAS is Gigabit-only too, but I don't use my NAS much either these days, since I just use external SSDs for my data now. Truthfully I would be totally fine with 1 Gbps down for internet service. More useful to me could be faster uploads since I use iCloud, but my current cable residential internet service maxes out at 50 Mbps.
(200 Mbps is available to business users, but the cost is extremely high.) A competing provider has fibre with 1.5 Gbps down / 940 Mbps up, but we also have TV and I hate the way their TV service is setup so I've stayed away for now.
An another note, I'm curious if Apple has fixed the memory leak in Photos. I had this problem where if I tried to export the entire Photos Library (which is nearly 700 GB), it'd use up the RAM and then eventually crash. I don't think having more RAM here would have helped, because it used way, way more RAM than that. If they fixed it though, I'm sure a 16 GB machine would be totally fine. (There are third party apps that can do this function without using much memory.)