The most immediate need we have to Taiwan is TSMC. Without them Nvidia, AMD and Apple are effectively dead, along with any car company, and a good deal of the products and services we use. A war with China would make 2008, 9/11 and the Internet bubble look, like tiny blips in terms of economic upheaval.
What bothers me most are three misconceptions about the ramifications of an invasion:
The first is that people don't recognize how important TSMC is, and how much its hardware powers.
The second is that people think US/European firms could just do the same. The skills, effort, time and money that TSMC has put in to be where they are is not easily replicated and we would happy if we could do it in 10 years, but that is doubtful.
The third is that China could just take over and run TSMC. You cant build chips in a warzone. And even if Chine would take over swiftly, and the infrastructure would be largely intact, each fab has thousands of employees, and all it takes for one of them to sabotage a fab is to cough in the wrong place, and it may never run again, and it would need to be abandoned. You do not need to smuggle in a bomb to disrupt a fab. Even if they did keep some fabs running, they wouldn't sell the output to the west.
On the upside, I get the feeling someone in the know has given the right presentation at the white house, because Biden looks like he understands this and takes this seriously, unlike many others.