See https://news.ycombinator.com/item?id=42518508. LuaJIT was about factor two slower than the V8 in 2020.

Of course, it doesn't have millions of dollars thrown at it.

It's also a completely different approach. Probably additional performance could be gained by implementing JIT support for additional LuaJIT bytecodes. But we cannot predict how significant this gain would be. If the concept has limitations, more money likely doesn't change much. We can also compare with the old Mono 3 version developed by a rather small company (Xamarin, before they were bought by MS), which follows yet another approach than V8 or LuaJIT, and which achieves about the same performance as V8; see https://github.com/rochus-keller/Oberon/blob/master/testcase....