I like that my dishwasher tells me when it’s done via app, and I can’t live without my robot vacuum cleaner.
Still, they’re on a separate vlan so if they get infected, the malware will look around like the John Travolta meme.
Keeping internet of shit devices on separate vlan is a good practice, but the apps on your phone still gather your data.
For the robot vacuum, when it brakes, you can look into valetudo supported models. It’s a firmware hack that kills the cloud component and exposes it through a local http server, works very well. As for the dishwasher you could probably use a localy controlled smart socket with power monitoring to send a notification via home assistant when the power draw goes below certain threshold. Either zigbee/z-wave socket if you have other smart devices on these protocols, or a wifi tasmota device can work.
This may be a bit too far for some, but I believe we should keep our data safe, and if this is what it takes, then I am doing it.