First: Can a newer router help.
Yes. especially if it is a 5GHZ job (THey are amazing story follows(
Second: You said "Wireless DEVICES" (Plural) so you are sharing your Maximum speed when you Wi-Fi but not when you hard wire. So if you have 10 devices connected to your router.. divide by up to 10 Or more if the thing vectors
The story:
Had breakfast at a Denny's with a 5GHZ router and high speed interned. .Hit 4516 EG BYTES Files loaded faster than from the hard drive on my Windows machine (I was using an Android that day and a Chromebook later) Amazing
Does slow down when more folks are using it.