Well strictly means without exception, but that's not how magic players use it when they say strictly better because they exclude corner cases. That's neither here nor there. Just clarifying I'm 100% aware of what it means in both literal meaning and MTG's jargon.

Now, if you're going to hold it to the degree of saying you can't say bolt or "Destroy target noncreature permanent" isn't strictly better than a vanilla 1/1, then fine.

But then I'm just going to turn around and say your accusation that this card's +1 is strictly better than Gisa's Bidding doesn't hold up in this sense of strictly better because that would be discrediting the fact that Gisa's Bidding has Flashback and for some reason counting in "life gain" into that +1 at the same time.

So either there's many examples of the +1s in planeswalker abilities being better than a card of the same converted mana cost, like scornful egotist compared to Ugin or Bolas, and this card compared to Gisa's Bidding, or they're all too different to properly compare to each other.

This Liliana can be answered with an attack, Gisa's Bidding can't, that's well with in normal mtg boardstates to make them night and day when considering "strictly better".