True. But you're focusing on the chain for the chain's sake. Remember the chain is a hack - a method of altering your behavior to produce a result - and that result should be the focus. Of course, I'm not going to lie and deny that the chain has its own intrinsic value, which only intensifies as it gets longer. But consider-
a.) The longer the chain, the less willing you are to break it, the more you learn not to let superficial things (like the futility of starting a new 3000-day chain) get in the way.
b.) The longer the chain, the more you've achieved your result, and the less you need the chain. If that result didn't happen, then you should reconsider the chain in the first place (as per my point above.)
Example of a.) As of today I have not missed a day of running in 485 days. After finishing a 100-mile ultramarathon 3.5 weeks ago, I got out and hacked together a 1-mile run the day after. Super painful, and took me 15 minutes, but it was an honest jog, and it counts. If my streak was much less than 460 days (at the time), I would not have continued the chain.
example of b.) The result of the chain? It helped me to finish a 100-mile ultramarathon, even at 6'6" 285lbs. If I have to break the chain tomorrow, and its length keeps me from ever starting a new chain, well - look at what I accomplished. I'd say it was worth it. And I suspect Seinfeld would agree regarding his chain.