All access which I think was the start of this idea is paid monthly. The total cost might be the same but the up front cost would be drastically different.
Still, it is not 100$ cheaper, it is identical price. "value" may be more than without the service but still price is the same.
Do people count that "this TV costs 1000, but it comes with 3 months of viaplay/netflix so it costs only 950 now!", I dont think so.
And also it depends of the target audience:
People that have invested in xbox ecosystem now = they probably already have the subscription, so maybe they give more value to the "free" 12months, or maybe they give less, but they would have bought more of it anyway
People that play on other consoles or don't play on any console currently = do they see 12months as great value, or do they think "damn, they force me to get this and without it the console would be 100$ cheaper!?"
Because many people are just like that, if something is offered as "free included in the deal" they think that it is actually added into the price already. Maybe some are more gullible and see it as great deal, like those crazy phone deals that cost much more than buying it with cash. (In my country you can buy phone with 1000€ or take 12-36month plan and it still costs 1000€, or usually 1-2€ less. no hidden fees. but in US it seems to not to be the case, plans cost more than direct purchase?)
then there are people that think "hmm, why are they giving it out for free? maybe it sucks?"
As playstation ecosystem "investor" I dont see any chance for xbox to offer anything to make their console my only next gen system. Even if they would give it for free and pay me 500€, I would get PS5.
Xboxs biggest flaw is that their games arent interesting, their ecosystem aint interesting, the whole system is just too "american" and don't fit for global cultures as good as playstations.
Their game pass just (to me) looks like that their games will be even less interesting in the future, because they are so bad and cheaply made that they dont even appreciate them by themselves. Like if they think their games are good, then why they value them as "almost free"? Because they are bad, cheaply made games. (mostly)
And because they offer their games so cheaply -> less money for devs? -> smaller budgets -> worse games
It already happened with other worlds. I liked the idea of the game before the release. But after they gave it away for almost free on xbox ->
it is worthless piece of turd in the eyes of devs, so why would I pay more than 5€ for ps4 version?
So unless next gen xbox offers way way more good AAA-games, I and probably many others have no interest in it. And desperate move of giving their stuff away for almost free because people would not buy em otherwise just validates my viewpoint that their games are bad, their system is bad and they dont even believe in it by themselves.
(I dont say that 69,95€ vs 1,00€ changes the game from good to bad, but it really gives out the mobile game vibe of trash games spammed on the market with low budget)