Numbers
That the same organization is being targeted yet again with a record-breaking attack indicates a DDoS arms race is developing between the attacker and victim
Not so sure about that. For DDoS attackers rely mainly on the number of machines they control, the CDNs, however, have got better at detecting the attacks through the packet signatures are blackholing them quickly.
If you want an analogy with the war: Russia has thus far favoured massive bombardment over combined forces attacks, so much so that it has been using anti-aircraft (S300 and S400) missiles for the purpose. On the battlefield the 10:1 superiority was for a while indeed effectively if slowly grinding the Ukrainian defences down. Then they got MARS and HIMARS and started taking the depots and in some situations the artillery out, whereupon the lack of air defence due to repurposing became a real problem. The analogy isn't perfect but DDoS and bombardment both rely on quantity and are vulnerable to changes in strategy.