Title text:
It's important for devices to have internet connectivity so the manufacturer can patch remote exploits.
Transcript:
[A store salesman, Hairy, is showing Cueball a dehumidifier, with a "SALE" label on it. Several other unidentified devices, possibly other dehumidifier models, are shown in the store as well.]
Salesman: This dehumidifier model features built-in WiFi for remote updates.
Cueball: Great! That will be really useful if they discover a new kind of water.
Source: https://xkcd.com/3109/
Honestly, having any of these vulnerable devices on your network is exposing your whole network, assuming the network is connected to the web.
Your best off using either a separate network for your smart devices with its own router, or setting up a vlan to keep your smart appliances and actual computers separate.