I think I'm happy with 1-3 planeswalkers per set. Honestly, it would be neat if we got a few more local, one-off Planeswalkers that come from the planes we're visiting. Lately it's just been a lot of the same old crew.

Planeswalkers are fun, because they can accrue a lot of value but are vulnerable to damage and attacks. They are typically must-answer bombs because they can accrue value turn after turn, and they often help support a deck archetype/synergy. As long as there are enough answers in the format for them, I think they're fine.