If the argument is facilities and staff, that's fine. But buying an outdated fab that won't compete with TSM isn't that big of a game changer, Intel already has tons of that.
https://www.anandtech.com/show/16621/tsmc-q1-2021-process-no...
Even Nvidia's RTX 3080TI is on an optimized version of Samsung's 10 nm node.
While semiconductor fabs don't have the useful life of say a railroad, they are valuable for far longer than the 2-3 years they are in the spotlight. I'm no expert in this area, but as the recent semi shortage demonstrates, it appears today's 'ancient' fab can be viable for at least 20 years if not longer.
Given the astronomical costs of both the fab and chip design for current nodes, we're likely to be seeing <=28nm sticking around for far longer to get their payback on the process nodes. So if you're Intel and you gobble up as much of the production capacity as possible, that would seem to be a prudent move as long as you don't overpay relative to how much you'll be able to increase prices with the greater share of the market. Think like Intel probably is: they're not thinking of being one of many semi players, they're thinking of being one of the last 2-3.