There are different layers of systems, driving and safety are not tied to the infotainment stack or anything cloud-based. Pretty sure there are industry standards that mandate this.
To answer the headline: it becomes everyone’s dream EV, a plain car without any bullshit. It won’t fail to start because of missing connectivity. The real problem is not having hardware support.
Regulation maybe? Regulate the honest and straightforward disclosure of risk at a minimum.
Opening up the market so that we're not forced to choose between a select few car brands lets consumers weigh the risks themselves, based on their own appetites and tolerance levels. Give them the information.
In the longer term, the introduction of risk opens up new markets where companies like comma.ai (open pilot) could flourish and fill gaps for EV companies that go under or fail to deliver on the service side.