Is Starlink capable of providing that much service?
Starlink has about 7,000 satellites currently in service and they come in a few flavors.
Here is a 2021 Estimate (pdf) of total full service concurrent users as of 2021 using Starlink Version 1 with a coverage of 211 satellites over the US, and the estimate was then 521,00 users, which was the beta phase.
Those Version 1 satellites had a per-satellite capacity of 20gpps. Version 1.5 has a capacity of 200 gbps and Version 2 Satellites have a capacity of 1 tbps, and the number of satellites has increased 400%.
Since Version 2 has only just started to deploy, we can assume a US coverage of ~850 satellites at 10x the capacity, which would support ~21 million concurrent connections. Limiting the target consumer to the users outside of access to modern broadband, and assuming that not all customers use full capacity downloads 24 hours a day (1 4k video stream users about 25 - 50 mbps) there is more than enough capacity, and when fully deployed with V2 there will be 30,000 satellites at 1 Tbps each, for a total concurrent user support in the US of 521 million.
Even at current capacity it has more than enough capacity to server rural US customers. Urban and Suburban customers who already have a selection of terrestrial broadband options (copper, fiber) would likely not opt for satellite, and current fiber capacity already far exceeds actual normal customer needs.
And at what cost? Isn’t it expensive?
The reason that there is $42 billion in subsidies available is because getting broadband to these remote homes and communities is expensive.
To put it in perspective, for $42 billion the US Government could afford to deliver Starlink to ~5.4 million homes for 5 years.
But that isn't even what that $42 billion is meant for, it's to pay the contract winners to run the cable to these homes and the consumers in the rural areas will then pay the subscription fees. In theory the savings to the end user will be the reduction in cost to the provider who won't need to recoup the costs of deployment.
So absent the "free" Starlink that I use as an example, the $42 billion would simply offset SOME of the costs to the end user. So if you offer $25 a month rebate, that $42 billion now lasts closers to 30 years... a span of time where all of these current issues will have long been resolved by new technology.