At the moment there appears to be ~no demand for older models, even models that people praised just a few months ago. I suspect until AGI/ASI is reached or progress plateaus, that will continue be the case.
For other use-cases, like translations or basic queries, there's a "good enough".
And I expect that over time the gap will narrow. Sure, it's likely that commercially-built LLMs will be a step ahead of the open models, but -- just to make up numbers -- say today the commercially-built ones are 50% better. I could see that narrowing to 5% or something like that, after some number of years have passed. Maybe 5% is a reasonable trade-off for some people to make, depending on what they care about.
Also consider that OpenAI, Anthropic, et al. are all burning through VC money like nobody's business. That money isn't going to last forever. Maybe at some point Anthropic's Pro plan becomes $100/mo, and Max becomes $500-$1000/mo. Building and maintaining your own hardware, and settling for the not-quite-the-best models might be very much worth it.
But the foundation models will eventually hit a limit, and the open-source ecosystem, which trails by around a year or two, will catch up.