I have around 30 YoLink sensors scattered about our house (mainly for detecting water leaks). And for a long time I only had the single hub in the basement on the complete opposite end of the house. I never had any signal issue and they've all worked flawlessly.
I haven't needed to change the batteries on a single sensor yet for multiple years. I did get 2 of their SpeakerHubs which also act range extenders, but it's completely unnecessary since the single hub is perfectly fine wherever you put it. I mainly use the SpeakerHubs as sirens, but they can also do text to speech, e.g. "(Loud Siren) Water Leak detected in master bath".
They've already saved me a couple of times.
I keep reading about all these standards for connected devices e.g. Matter, but in the end these just work perfectly for my use case.
Kind of. I use their waterleak sensors and pair them directly with their YoLink Siren. The siren will go off without cloud, internet, or even power (until the batteries run out).