It's no different than the risk of upgrading your motherboard's bios. If the update fails to finish writing (like if the power goes out during the update) it will leave the firmware in a broken state and won't boot.
Some systems mitigate this risk by giving you two different bios regions so you can write to one and leave the other pristine as an emergency backup if the update fails. Other systems put the bios on a removable chip so if an update fails you can pull it out and rewrite it with dedicated hardware or another working computer.
For inexpensive laptops that are built to the cheapest price possible and where 99% of users will never mess with the bios they don't include those kind of features. So you just have to accept the risk that you could destroy the machine if the update fails, and try to take reasonable precautions like making sure the battery is charged up and it's plugged in while updating the firmware.
Some systems mitigate this risk by giving you two different bios regions so you can write to one and leave the other pristine as an emergency backup if the update fails. Other systems put the bios on a removable chip so if an update fails you can pull it out and rewrite it with dedicated hardware or another working computer.
For inexpensive laptops that are built to the cheapest price possible and where 99% of users will never mess with the bios they don't include those kind of features. So you just have to accept the risk that you could destroy the machine if the update fails, and try to take reasonable precautions like making sure the battery is charged up and it's plugged in while updating the firmware.