It is fine filler but hurts the average power level of your deck even if it does make it safer
But if it sticks, it quickly dominates
You can play this black ramp piece in other color combinations thanks to Urborg, Tomb of Yawgmoth, but those decks make this black land a weak half of a 2-card combo
As with any cards with two effects that have synergy, the design space for this mechanic is limited
Unlike Crashing Footfalls however, Primeval Titan has been around for many years already, has seen play in multiple other decks in the past (Scapeshift and Titan Breach) and is still kicking strong as a Tier 1 contender despite multiple bans (Summer Bloom, Field of the Dead) in the past
If youre willing to take the efficiency hit, you can also include slow-blink creatures, like Flickerwisp, for some additional redundancy