Is the switch always "on" and the sensor then turns on the light and you just have to turn the switch "off"?
And then if the switch is turned "off" will you need to first turn it "on" again in order to make the automation work properly again?
By using occupancy and time of day conditions I can have multiple rules to turn on lights to different brightnesses at different times of day. I turn on sets of lights vs individual lights so it’s not the absolute most efficient in terms of power but on the other hand having lights turn off automatically is a good saver when you have kids.
I use Lutron Caseta wall dimmers and dimmable LEDs everywhere so they already have a nice fade-off effect. I once tried to code a fade-on effect but it turns out that instant on is preferable so I gave up on that (it was unreliable anyway).
For low traffic areas like closets I use Lutron Caseta motion sensors; they work great and have very little configuration.
One note of advice - there is a lot of grey market Lutron stuff on Amazon; you can get burned by clones or up-labeled stuff that doesn’t function exactly as advertised. I would stick to buying at a home store or buying from the Lutron store on Amazon.
So it doesn't matter if you manually turn them on/off - they remain network accessible.
This is why they're strictly nicer to use than smart bulbs. Even if you want smart bulbs, you'll probably want smart switches too, but if you have smart switches you only really get a benefit from smart bulbs if you want to control the colour of the light.
You can control brightness of a smart bulb. Not all dumb bulbs are dimmer-friendly. That said, you can always replace those with dimmable dumb ones.
But also, smart bulbs with a dumb dimmer is the worst combination, so if upgrading somewhere, if it has dimmer switches that's an extra reason to replace the switch too, irrespective of whether you also replace the bulbs...