There were multiple competing stores and sometimes even the developer's own site. The prices were ridiculous, partly because everyone had to implement their own payment and distribution systems. If the software didn't work or there was a problem it was rare to get a refund. Most of the time your contact info was readily sold to "partners".
Apple's cut of sales for the service they provide is pretty small compared to the costs of doing it yourself. There's many of thousands of developers that are enabled by the fact they don't need to host their apps, handle billing, or handle user accounts and PII.
If you seriously think prices to end users would decrease if Apple took a smaller cut you're deluding yourself. If developers are making sales at current prices there's zero reason for them to drop prices even if their overhead drops. Prices are set by what the market will bear and only have their lower bound set by the developer's overhead.