Neither. They are both trash that belong in the depths of PU and rot there while Beedrill kicks ass. But yeah, They both have their pros and cons that are basically what the other Pokemon lacks.
Pikachu
While Pikachu has the major tool it calls a Light Ball, to massively boost its offenses, it is also its main downfall in that it will remain a slow rat. Pikachu also has the crappiest defenses and will most likely be 2HKOed or OHKOed by a neutral hit. That being said, its Light Ball is the only reason why you should even consider Pikachu. With Sticky Web/Paralysis support, Pikachu can shine and show its potential when it nails the KOes with hazards included. Pikachu also has its trademark STAB in Volt Tackle to set it apart from the likes of Electivire.
Pikachu @ Light Ball
Trait: Lightningrod
EVs: 4 Def / 252 SAtk / 252 SDef
Timid Nature
- Grass Knot
- Thunderbolt
- Hidden Power Ice
- Substitute/Volt Switch
Pikachu @ Light Ball
Trait: Lightningrod
EVs: 252 Atk / 4 SAtk / 252 Spd
Hasty Nature
- Extremespeed
- Volt Tackle
- Brick Break
- Grass Knot
Here are Physically Based and Specially Based Movesets of Pikachu for you.
Raichu
Imma be honest, Raichu is complete ****. It is outclassed at everything it does, and it has no offenses to even hold its own in battle. There are way better options than Raichu in the Metagame, Rotom, Lanturn, and even Dedenne is better. Raichu can boost its offenses with Nasty Plot but its not worth it if its Defenses are not great at all. Pikachu has its niche of massive power, the thing that Raichu would wish for(has great speed).
Raichu @ Choice Scarf
Ability: Lightningrod
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Volt Tackle
- Knock Off
- Grass Knot
- Volt Switch
Raichu @ Life Orb
Ability: Lightningrod
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Nasty Plot
- Encore
- Thunderbolt
- Focus Blast
Those are Smogon suggested movesets for Raichu, similar to Pikachu but just with items to help with its speed and offensive potential.