With PoS, you don't have any operational expenditure, and the sticker price of your capital expenditure stays the same, and you can get it back when you unstake.
They're not the same.
It’s just that the depreciation is slower, and less expensive over time than GPUs or ASICs.
Maybe this isn’t the case with some of the other DPoS chains out there, where people can delegate their stake to validators, making it unnecessary to run any hardware.
Interestingly, unstaking is not actually supported by the network yet so the staking only goes in one direction. The price and demand impact when that does go live will be interesting to watch.
Before we had ~3 groups (miners, holders, users) that all kind of needed each other. Now there's no more miners. Given that crypto loves zero-trust and all that, I think it'll be an interesting experiment to see how the randomness of staking allocations plays out; if randomness streaks towards major capital, it'll look like they're favoring themselves and their stakes will accumulate %-wise increase at a higher rate (centralization!). The other "random-streak" outcomes aren't as bad (imo) and there's some game theory around this topic that I'm only topically versed in. Complicated by the part that miners did have some of their own problematic incentives and externalities.
In summary I view it as moving away from an unstable 3-body problem down to a more stable/centralized 2 bodies, one of which has greater influence. Hopefully good stewards and all that, but instead of forced cooperation among the 3 we now mostly trust 1 group.
With PoS, without significant operating expenses, you can simply use your earnings to perpetually increase your stake.