Unless the Mesh system has IPS built in, mesh itself won't help against a virus nor malware. From what I see, people buy a mesh system due to dead spots within the home and they find it easier to install a mesh system as you don't need to run ethernet cables. A mesh will not provide more speed; the wireless device is probably closer to the mesh device, so it seems faster due to a stronger signal or the mesh device has better antennas than the base all in one wireless router, so yes, faster wireless speed, but not overall internet throughput. I prefer wired access points and have two inside and one outside in the backyard. A good router should have IPS built in, so you should start there; I use Ubiquiti products and my UDM-Pro has IPS and its enabled. Cameras and IoT should always be up to date with firmware, default passwords changed (a plus if you can rename the default admin account) and on a seperate VLAN that blocks traffic into your main network. In my case, my hardwired cameras and IoT are on separate VLANs than my main network, so if those devices are compromised, my computers are protected. I have separate SSIDs for guests and wireless IoTs and those are also on separate VLANs than the main network.