This metaphor gets repeated a lot for some reason but using a gym subscription has an upper bound. If one subscription could be using 10000 different machines at the same time their model would be entirely different.
And there's a hard place that everyone freaks out at API prices and on-demand Opex models outside of a niche (I use API for personal research for quite focused queries and slightly more reassurance on being the customer and not the product) but this is very competitive + not sticky.
Overall it would go through weekly usage within 40 minutes, if not for 5h session limit.
Running on 10000 computers will just hit all the limits at once.