Why didn't Yoda use his lightsaber to block Force lightning?

Why didn't Yoda do that in both of his fights, instead of manually deflecting or absorbing it?

Yoda was not wielding his lightsaber in either of the fights when he was attacked with force lightning.

In the case of Obi-Wan and Windu, they were both already wielding their lightsabers when they were attacked with force lightning which is why they used it.

Perhaps the quick nature of a force lightning attack is such that Yoda would not have had enough time to wield his lightsaber in order to defend himself. It looks like he did not even have time to defend himself against Palpatine's attack.