SOEs are 50+ years old, legacy titans like BYD ~30+, older than Tesla. Tesla tier tech upstarts nio, xpeng, li ~10. But ultimately who cares, the big / influential players are arguably too big to fail by local gov standards whose going to keep going forever, or consolidate under players that can keep them going. The brands too small to survive aren't seriously exporting to the west anyway (like yes there's brand/marketting plays like hiphi which is basically vinfast tier). Car makers, especially ones with tech stack are not Luckin Coffee, if state/province wants to keep a strategic brand going forever, they will. Just like western auto pork barrel due to "excellent" financiered bookkeeping and auditing.
Local gov can only prop up so long as they have money; and their balance sheets are strained due to ballooning debt funded by a deflated property bubble.