The sales are a nice thing but for me the biggest benefit of Steam is knowing that I can use my games library on other/future devices.

My games have been working on my desktop from 10 years ago, the SteamDeck, my laptop and likely any future computer I buy that runs Linux.

Console stores also have sales. Often with pretty huge discounts. I just bought a bunch of games on Xbox in the 1-5 dollar range. I see similar sales on PS5 all the time.

Honestly, these days, Steam, PS and Xbox game sales prices are pretty much in the same level now. Ten years ago it was very different. Recently I was thinking whether to buy Resident Evil 4 on Steam or on PS (had the same price 9,99€). Got it on Steam in the end. Though, Steam still wins on regional pricing as they support more local currencies.

Only the Nintendo store have games priced usually a bit higher.