It's not really. I've had a test bench with smartphones at work with open smartphone test farm and about 50% of them cracked their cases open after a year or two. It is not a joke. It really happens. None of them actually got to the point of exploding but it didn't exactly look "safe". Of course I replaced them when this happened. Sometimes it took a while because they were on a stand, we only controlled them remotely so it would take me cleaning the stand or something to notice something was off.

Still, it served our support team really well during the pandemic. They could test wifi setups at the office with different android versions even when they were in a country that was on lockdown themselves.

OpenSTF was great: https://github.com/openstf

I think it's now been replaced by DeviceFarmer: https://github.com/DeviceFarmer/stf