It's only too high if they demand exclusivity.

And they don't.

They are providing PLENTY of value to anyone who is listing their games there.

Would I like to see them do more now for small and independent outfits? I would! but 30% isn't that much comparatively to the old days of buying physically distributed things in a brick and mortar store.

I remember buying final fantasy 2 (4) on snes and it cost 95$ US this was 1988 or 1989

Which was about 129 CAD (the exchange rate is between usd then and now is about the same conveniently for this tidbit)

Today after years of inflation it would cost about 250-260 USD or 340-355 CAD

I don't fucking miss those days at all. And while there are multiple factors here in play, this is entirely fair to charge silksong 6 dollars ish per sale on a 20 dollar sale whilst the failing AAA games 30 dollars on a 90 dollar sale. There is a cost involved and it is because of steam, specifically steam, that made digital distribution what it is today. And by that I mean they have set the standard for what is a healthy location to sell your digital goods.

And to give an example of what garbage (yes you Tim Sweeney you giant whiny fecal faced fuck) digital distribution for games would look like if steam didnt actually do a great job, look at books.

Buying books on through amazon you pay more for them then you used to for a physical copy of the book itself.