I always wondered how big the potential console market really would be. Let's suppose Microsoft, Sony and even Nintendo would give away their consoles for free, not even tied to a subscription. let's suppose they calculate they still would make enough money just through regular subscription fees, selling of games, dlc's and accessories. That would force the biggest console market possible. How big would it be? 300 mil., 500 mil. or more? Personally, I think, it wouldn't be much bigger than 300 mil.
To clarify, I'm talking about unique current gen console owners (Switch, PS5, Xbox Series-X/S), i.e. one who owns multiple consoles counts just as one.
7th gen was over 270M counting only home consoles, with MS botching its head start with RRoD, Sony botching its launch with initially horrible prices and Ninty killing early an invincible market leader.
A free HW gen, with at least Ninty offering portable capability too would reach at least 400M users IMVHO, but probably, with enough free and low price games thrown in the offer, even more, as it would attract a lot of currently mobile-only gamers. It could attract a slice of PC gamers too, the most casual ones and those that have a PC still good for work or browsing, but getting old for new games and not wanting to upgrade it, but not hardcore ones that are ready to spend more than a console price for a gaming PC, and those that like a more free gaming market.
Yes, I get you mean unique gamers, not units, but considering that multiple same-gen console owners are a small minority outside of the richest countries, and that there are many gamers that don't even buy a console each gen, and that PC users are far over 1B and mobile ones more than twice, and around 30% of PC ones and far more of mobile ones are at least very casual gamers, and 10% of PC users are estimated to be more dedicated than casual gamers, the potential market for free HW console gaming is huge.
if we talk about units sold, well, actually given for free, many gamers would get at least two free consoles, as Ninty games don't overlap much with competing platforms ones, so we could expect at least another 100M units for 400M gamers.
BTW, if you consider that Sony and MS consoles are general purpose multimedia devices too, we could expect even more units delivered, even to non gamers, but those ones wouldn't contribute to gaming market, so I accept it's fair to not count them in your scenario.