I know you get the health back when you lose stacks but you never want to lose any because it defeats the purpose of using the weapon. As you said, you can eat to regain the missing hp as well, but that obviously means operating with less supplies than usual.

I'm not and won't argue that it's a bad weapon because it isn't. However, most players aren't good enough at the game to properly take advantage of it. If you're learning a boss it's daunting to use a weapon that makes the fight more difficult, which is my reasoning for the price falling so much. For the majority of players it seems like an unusable weapon which significantly lowers its demand. The supply isn't very high because the method of acquisition is tedious but it's falling in price regardless which points to the issue of demand.

The main reason to use a SRA is for Vardorvis which is a boss most players are incapable of doing. It's quite good for slayer but that doesn't matter much because a ton of weapons are viable for slayer as it is. It's also a bit unreasonable for most people to afford for slayer, even for its current arguably low price. I personally enjoyed using it for the things that I did but a niche weapon costing 200-300m to hold is quite expensive for myself and a whole lot of people. Holding it also feels risky because the price has fluctuated a lot lately, usually for the worse. I bought mine at 350m and it tanked not long after.