While I prefer SmartSwitches myself and generally advocate for them over smartbulbs, there are advantages to SmartBulbs that should be ignored.
First and foremost: No wiring! I’ve heard that in some areas you are actually REQUIRED to hire a certified electrician for any electrical work, even if it’s in your own home. This means a hefty labor cost even for something as simple as replacing an outlet or a switch. (Of course, this would be pretty hard to police but if you wanted to follow the law in these areas you shouldn’t do it yourself.) And even if it isn’t against the law, if wiring it not something you are comfortable messing with, replacing a bulb is a lot easier.
Second, cost: The cost of smart bulbs has really fallen a lot. SmartSwitches has reduced in price as well, but still not as much as bulbs have. Just replacing 1 or 2 bulbs is still probably cheaper than switches.
Third, complexity… okay, this is sort like #1, but in some situations you want power to the device always but still ability to turn on/off the light. For example: A ceiling fan/light that doesn’t have separate power for the lights and fan. Putting in smart bulbs lets you keep the wall switch on all the time to power the fan when you want to, but still control the lights automatically.
Probably a few other things I’m missing too.