youngling level

The static electricity from Tarkin's slippers level.

That was a substantial blast of Force Lightning.

Jedi Master Mace Windu struggled to cope with a powerful blast of Palpatine's Force Lightning even though his defenses were shaped by a Lightsaber and Vaapad (unique combination), but this worked for him. Master Kit Fisto and Darth Vader could use a Lightsaber to contain and/or deflect such bursts but this might not be sufficient in their case. Master Yoda had proficiency in Tutaminis to help him absorb and/or deflect such bursts but this barely helped him - perhaps he could do better with a Lightsaber but this is not established in writing.

I recall Luke Skywalker coping with a blast of Force Lightning from Palpatine in Dark Empire in a duel; Luke got back on his feet afterwards. This was a limited blast of Force Lightning however, and not a continuous stream that WE see in Episode 9.

Rey Skywalker was successful where others failed in a long time. Oh well...