Look at the Samsung PM963 photo

Notice lot of tantalum capacitors, they are here for a reason. During sudden electricity shutoff SSD firmware is designed such that drive will safely finish operation using remaining charge (you can still have written file errors, but all else will be perfect).

Modern drives (except some server parts) got rid of this $3-5 (total) parts, and instead put thin alu "heatspreader". Such thing overheats instantly (up to 60 seconds before throttling) even at open bench. But placing $2 heatsink is beyond most brands brain level. And even ones that do it like to put thik thermal pads under it and allow designers to decide heatsink shape and form (read - make it 5-10 times less efficient).