Why is price comparison still so bad in 2026?

I’ve been thinking a lot about how surprisingly difficult it still is to compare prices across major online stores. Even in 2026, Amazon, Walmart, Target, Best Buy, Costco, and dozens of others all show different prices, different discounts, and different stock levels.

Google Shopping is incomplete, browser extensions feel heavy, and most comparison sites are full of ads or outdated data.

Why is this still such a hard problem? Is it technical, legal, business incentives, or something else?

I’ve been experimenting with my own approach to this problem here: https://yourpricehub.com — but I’m curious how others think about the broader challenge.

Would love to hear perspectives from people who’ve worked in e‑commerce, scraping, or pricing systems.