You can have both options, but you can’t use a dimmer switch (networked or not networked) in combination with smart bulbs unless it is specifically designed for that purpose. Otherwise you run the risk of burning out either the switch or the bulb.
There are a couple of zigbee dimmer switches specifically designed for control of smart bulbs: the Phillips hue dimmer switch, the Lutron connected bulb remote, and the new Osram Lightify dimmer SmartSwitch. These don’t work directly with smart things yet, but can be a good parallel means of control.
You’ll find more detailed discussion of which switches to use with smart bulbs in the following thread. Although the thread title says “Hue” most of what is said there applies to any brand.
BTW, at our house we mostly use Hue white bulbs (very reliable, typically $15 at Best Buy) and our primary means of control is the Amazon echo. We leave the existing switches in place and add the Zigbee switches I mentioned above as a parallel means of control. It works great for us, but might not work at all for someone else; it just comes down to your own needs and preferences.