@HereturbiesWalt
First, i have no experience with Lutron smart stuff, so i cannot comment there. But a couple of questions i can answer.
"Kasa is cheaper and does not require a hub, but what if my router gives out? Do my switches also stop working?"
When the router goes out, Kasa switches can be controlled manually, like any other switch. The simply loose communication with your other devices, including your cellphone.
A hub does not work when the router is out. The hub is a programmed device that works through the router. As to the advantage of a hub, it can be advantageous because it is essentially a little computer. The memory can be larger, more programmable and more sophisticated than the logic programing of an individual device. So it really depends on what tasks you want smart devices to accomplish. In short, don't worry about it too much, because the house and your needs will change over the years. Devices and applications will come and go. Focus on your immediate vision.
"buying all smart bulbs since the cost is decreasing"
Smart bulbs are nice. Their color and brightness are easily tuned. i found that Sylvania is extremely easy to work with, compared to lights that use Smart Life, Tether or Lamplux. But smart bulbs have some problems in some situations.
1. They can loose their programming and then have to be re-setup. Annoying and time consuming, especially with Smart Life.
2. Remember, generally speaking, they have to be turned on all the time and have electricity to be "smart". When you put a smart bulb in a light circuit with a switch, people naturally turn it off. i mean, when you want it off, you either have to pull your cell out and bring up the app, or tell Alexa to turn it off, or shut off the switch which makes it a "stupid" light and sometimes looses it's programming.
So in some situations, i like having a smart light and hiding the switch. LIke in the kitchen, i have a few smart light bulbs that Alexa can turn on when my hands are full, or i'm carrying a cat or a baby or an angry alligator, or all three, smart lights are handy.
3. But the only way to control a smart light is with the router. So, remember, when the router is out, leave the angry alligator in the bathroom. i learned this the hard way. Sorry Fluffy.