I'm not trying to tell you you're wrong I'm just curious given I've got a house full of smartthings and hue and alexa and nest etc etc and haven't ever felt the need to go this route, thought I might be missing something.
I can't honestly think what I'd use bluetooth for anyway but I guess we have different uses.
I have smartthings for all my samsung appliances along with motion/leak/door sensors. Hue for all the lights (including INNR ones as I go with cheaper alternatives for the most part) and it all just knits together nicely with hubs stuffed in a cupboard.
The cupboard isn't very elegant I'll give you that and I had to get a switch to cope with it all but once it's done I just forget about it.
I do remember the one time we had a power cut a few years back a rude awakening with all the lights on full blast and not being able to turn them off but it's happened once and since then I think Philips have added a thing where the lights come back on in their same state.
My main issue is that I have far too many smartthings sensors and recently moved house so there's tons that are all named the wrong thing but thats just a case of deleting it all and starting again.
That said, I've not ventured into the cheap sensors etc, I did wander into trying to use the smartthings homebrew thing before and backed away with a NOPE.
I don't mind a bit of hackery on a project, not on my house