While I agree with a lot of what you say, there is one major problem with legacy car makers coming out with all the Tesla competition you’re talking about: There is no batteries for them. There is currently no other battery supplier (besides Tesla themselves) that can produce enough batteries for even one legacy car maker to produce a mass market electric car, let alone multiple makers. Tesla didn’t build a huge battery factory for the heck of it.
IMO, there is no way a legacy manufacturer is going to be able to produce a mass market Tesla competitor unless and until they invest in the battery manufacturing infrastructure to support it.
There’s a reason they all haven’t built a competing car up until this point, and IMO, this is it. And to my knowledge, none of them have even started to solve this problem yet.
Until the battery manufacturing infrastructure exist to supply the legacy car manufacturers with batteries for their cars, Tesla has the market cornered, save for the few smaller battery niche vehicles currently being sold, but IMO, they aren’t even in the same class.