I agree Obito is not an insta win. However it really is close to being one against blitz teams, specially lightning ones.

Turn 1 prompt mystery which causes immobile and debuff to any ninja, including ninjas protected by lightning armor or the FM mystery. This deals damage (so no more WB asuma buff), removes debuff (no more iruka or LM buff) and causes immobile (no extra 40 chakra from mabui or 3 attacks from LM).

To make matters worse it can't be interrupted since obito dodges the first mystery or attack from every round.

This is the text book guide of how to counter the 1010 blitz by stopping mabui before she gives chakra to tenten round 1, as well as survive round 1 against LM teams without your ninjas dying.

Han on the other hand is more a soft counter since he will only remove LM and iruka buffs (maybe barriers as well? there are contradictory reports on that last one). He is also a tank so it increases your chances but since he doesnt do damage WB asuma buff remains and LM attacks 4 times (probably teams gonna remove sword buff).

Currently as long as you have higher initiative than your opponent blitz teams are almost guaranteed to win (mind a too large BP gap though). With the Han and Obito this changes and blitz teams will have a harder time to win as many fights.

Most players have been saving scrolls for han since they learned that Roshi is hard to use at low BP, se do expect to see more Hans than Roshi's next month.