I guess it depends on what you mean by "better".

SAR is a niche within a niche. I can totally understand why Soylent is 1000x better than other options.

But most backpackers are doing it for fun. Reducing weight and space is great, but there are plenty of much more enjoyable meals that are only marginally heavier/bulkier.

At least for me, cooking a good meal before bed is my favorite part of the day. I'll happily carry an extra pound or so to make that happen.

TBF, a lot of purely recreational backpackers care less about the pleasures of life. The type doing 14 hour days and so on. But that's a small market, and all the folks I've met on trails who are doing that sort of thing tend to be pretty price sensitive. Young folks with few savings taking a few months off work don't have three months of Soylent money ;-)