I think there may be 4 different furnace manufacturers in North America and how many brands are there? For instance Carrier makes Payne, Armstrong, Bryant, Tempstar, and Heil. There is a huge difference in price between Carrier and Tempstar and the difference in reliability is probably negligible.
That’s more common and applies to a lot more things than most people would think.
A former employer of mine made the house brand dog shampoos for WalMart, Target, Petco, Petsmart and a few smaller boutique brands. The only difference between the products was the packaging. Prices ranged from $2.50/bottle to $19/bottle depending on the brand and retailer.