Earlier quoted context omitted.
This one: https://www.aliexpress.com/item/1005005657383634.html?spm=a2...
You're running all your flat's power through that $14 Chinese rubbish and never assumed that shortcuts were taken or quality would be an issue? How do you know it will continue to function as a circuit breaker and isn't just a piece of wire inside? For the uninitiated, CE marking is meaningless (it allows for self-certification). I'd like to see Big Clive do a teardown of one of those.
Solid state relays have widespread fraud. Like 60% of the ones on amazon will catch fire or fail before they hit the rated current. Trade suppliers generally don't sell them at >30 amps.
Regular relays up to 10 amps are cheap and reliable. Beyond that, they get expensive surprisingly fast, and the reliability is hit or miss. They fail in numerous ways, but the most concerning one is the plastic case melting and catching fire. The chance of failure depends on the nature of the load (capacitive or inductive loads will dramatically shorten a relays lifespan).
In my professional career, I have witnessed ~20 of the above devices failing, with melted bits or burn marks, but of that sample none has burned down a building, yet. But I'd say that was more down to luck than good design.
In general, I would trust a china-device for monitoring power, but not for switching anything more than ~10 amps (1 outlet).