There are a lot of players in the hypothetical world of , but only two of them are big enough , or at least big enough for those taunts to land with meaning. I’m talking about Waymo and Tesla of course, and I say hypothetical because it’s still not clear to me that Level 5 autonomous will ever be a real thing.

You could sense the seeds of it in April 2018, when Waymo CEO John Krafcik was and he gently pointed out that Tesla’s technology was simply not self-driving. Or maybe it was a few days before that, when Krafcik at Tesla CEO Elon Musk saying that human driving might someday have to be outlawed.

By the time Waymo that it was opening up its autonomous taxi program to the general public, the beef had escalated, with Krafcik needling Tesla on Twitter about the clarity of Waymo’s . Those warnings make it clear that the Waymo Driver is in control at all times, unlike Tesla’s system, in which the human driver must still pay attention.

Then last week happened. Krafcik said that Tesla is simply “no competitor” and that it’s “a misconception that you can just keep developing a driver assistance system until one day you can magically leap to a fully autonomous driving system.”

That latter misconception being Tesla’s whole strategy, in that it wants to get as many people using its system as possible so it can gather as much data as possible, basically using its customers as testers. The desired end result would be that the system will learn from all of this data and, you know, make the leap to Level 5 somehow.

Of course on Sunday night Musk had a response to that, too.

Every bar fight ends on the floor, as they say, and so it would probably be wise for both of these guys to simply focus on their own companies and building the best product they can, even as they ostensibly toil at a goal — complete autonomy — that . Waymo may want to stop at Level 4 autonomy, like it already has in Arizona, while Tesla’s Level 2 system is simply that, a Level 2 driver assist system that needs the driver to pay attention.

The likeliest outcome, of course, is that a year from now Waymo will still be at Level 4 in a few places and Teslas will still be at Level 2 — and probably the same for the year after that, too.

What’s become abundantly clear since autonomous driving first became an aspiration is that this is a marathon, not a sprint. And we’re probably still at the beginning. So if you want to talk a little shit, you should also know that’s energy you could be spending elsewhere, though I doubt either of these two will ever stop.