If you're working from home and sending files (especially larger ones), I'm all in for more Internet speed...depending on where you are, it can be relatively cheap and makes a big difference.
HOWEVER, most a lot of "home" routers are a bottleneck - check your internet speed, if you're not getting nearly 1G now, upgrading beyond 1G may be limited on your router. When I went to 1G fios I had to change my unifi router, got the UDM-PRO and wouldn't be able to use it for more than 1G. If FIOS ever goes 2G in my area i'll probably go DIY FW.
And if your NAS & PCs support 10G....it makes a difference moving files around a LOT faster and a nice core for the 2.5G WIFI connections.
The Roon stream isn't much BW to worry about (Shout out I love the new ARC in the car).