Someone could come in with a good electric car and eat Tesla's lunch.
Tesla's most serious competitor is BYD and they have only produced 35k cars to date. Chevy has sold about 65k Bolt EVs, but they are reportedly losing $8k~$9k per unit, so I would hardly call that serious competition. All of the recent "Tesla killers" -- Taycan, E-tron, I-pace -- can barely match the specs a 2012 Model S, and fall far short of the latest Teslas. By the time they figure out how to produce more than a few hundred of those vehicles per month, Tesla will have added another 50~100 miles of range to their cars.
An electric car lacks the range and short refill time for the typical cross country drive, or for taxi service, or for a delivery vehicle, or for patrol (think police and security).
On the contrary, some police departments have already begun buying EVs. Granted, it's not the best fit for every department, but municipal police cruisers seldom travel more than 100 miles on a shift, so there's plenty of time to recharge. Then there's Amazon, which recently contracted to buy 100k electric delivery vans from Rivian. Fleet operators are a prime market for EVs, since they can save a ton of money on maintenance and fuel.
Andrew Yang is talking about, the use of nuclear power and synthesized fuels. We get that to market and every internal combustion engine becomes carbon neutral
That's all well and good, but it will take many years to build out that kind of infrastructure. The nukes in particular will take years just to get permitted. The ICE-to-EV market flip will be over with long before then.
These other companies can buy a Tesla vehicle, tear it apart to see how it works,
Or they can just buy the complete teardown report from Sandy Munro. But even that won't solve their problem.
The real challenge for OEMs is what you hinted at before: inertia. The bulk of their expertise and investments are in a handful of key areas: combustion engines, body parts, general assembly, and painting. Most of the other stuff, from software to seats, is outsourced to suppliers. (Tesla is vertically integrated to a degree unmatched in the industry.)
More to the point, they are in a catch-22 situation... Moving into the EV space will require a significant investment, which can only be funded by selling more ICE cars; but selling EVs will cannibalize their ICE sales. And along the way, they'll also be paying out billions to Tesla for zero-emission regulatory credits. Oh, and they each typically spend $3~$6 billion per year on advertising, which Tesla famously does not spend a dime on.
Their only saving grace is that Tesla can only build out its capacity so fast... it will take several years to build enough factories to challenge the incumbents in production scale. But before they get that far, the market for ICE vehicles will already have started to slip, as the rate of car ownership is already starting to drop, and the superior TCO/economics of EVs becomes more widely known.
Even if they start retiring their ICE production lines, they can't just switch over to EV production so easily... because you can't just buy 20GWh of batteries off the shelf. You either need your own factory or a long-term contract with a large producer. Most of the incumbents to not have such deals in place.
Some of them will survive, but many will not. It's that simple.