Joe,
I primarily use devices such as smart light switches and outlets (TP-link, Smart Home) that don't require separate hub/s to operate.........e.g., device/s are operated directly from your wifi router. This helps cut costs at times
I run smart cams (Samsung) and my lawn sprinkler controller (Hunter) are also direct connect to my wifi. The one exception to direct wifi is my hub based roof top electronic weather vain system (AcuRite) that also integrates several remote temp sensor (one in deep freezer, one in squirrel house with smart cam) and water detection/flood detector (several in basement at floor level)..............
My amazon echo then operates lights/outlets directly as well since I want hands free voice activated within my house at times (coming in a dark house with arms full of groceries, you know......"Alexa, turn on the house" where I have grouped my family room, dinning room, living room and kitchen lights as "house" within the Echo app and of course each may be controlled individually by the Echo.......e.g., "Alexa, turn on the kitchen light", ."Alexa, turn on the coffee pot"
All above systems can be ran/accessed and set via apps to generate alerts/notifications to my smart phones (or desktop/laptop PC's) of motion and/or sounds (camera/s), temp out of range, freezer/furnace crapped out etc (AcuRite), water detection/broken pipe, etc (AcuRite), over or under current usage on sprinkler solenoids and feed wires (Hunter internal), water usage out of range on zone, sprinkler feed pipe leak, head/s plugged etc (Hunter, external flow meter), real time wattage usage of plugged in devices (TP-Link), real time control, timer and away scheduling of lights and outlets (TP-Link).