Yes, the Steam Deck is great, and Steam is definitely one of the best games platforms there is. And Valve has done great work supporting Linux and open source development, and forcing more transparency for sellers on Steam.
But I feel like people sometimes just love valve for everything they do. GabeN is still a billionaire, buying super-yachts and stuff. Valve makes a ton of their money from gambling on loot crates in CS2 and TF2, and have not done enough (imo) to stop even more predatory third party item gambling sites. And whenever I bring stuff like that up people keep defending Valve.
We should be able to praise their great games and hardware, at the same time as criticising other parts of the company.
The 30% is not standard. Steam is practically the only one that takes this much on PC and beyond. Only console stores can be compared to it, but that’s at least justified by the consoles themselves being sold at a loss.