I think we're talking about 2 different things. I'm not sure where Roblox fits into what I said.
The problem I describe is companies pushing towards the "rent" model vs. "buy to own". Nvidia was just an example by virtue of their size. Microsoft could be another, they're also eying the game streaming market. Once enough buyers become renters, the buying market shrinks and becomes untenable for the rest, pushing more people to rent.
GPUs are so expensive now that many gamers were eying GeForce Now as a viable long term solution for gaming. Just recently there was a discussion on HN about GeForce Now where a lot of comments were "I can pay for 10 years of GeForce Now with the price of a 5090, and that's before counting electricity". All upsides, right?
In parallel Nvidia is probably seeing more money in the datacenter market so would rather focus the available production capacity there. Once enough gamers move away from local compute, the demand is unlikely to come back so future generations of GPUs would get more and more expensive to cater for an ever shrinking market. This is the vicious cycle. Expensive GPU + cheap cloud gaming > shrinking GPU market and higher GPU prices > more of step 1.
Roblox is one example of a game, there are many popular games that aren't graphics intensive or don't rely on eye candy. But what about all the other games that require beefy GPU to run? Gamers will want to play them, and Nvidia like most other companies sees more value in recurring revenue than in one time sales. A GPU you own won't bring Nvidia money later, a subscription keeps doing that.
The price hikes come only after there's no real alternative to renting. Look at the video streaming industry.