This Town Ain't Big Enough has now been a promising part of two intriguing new decks in three months, so while the card could come down in value once the shine wears off Esper Self-bounce, it seems likely the spell will continue to find spots in new archetypes
That shuts down things like Force of Will or Fierce Guardianship, pretty commonly played in Commander
Yawgmoth's Bargain is the most well-known of these, breaking during the Urza block thanks to multiple ways to get it on the board quickly
They're not quite the kings of durdle, but they're close
As much as having the filtering in the deck is nice, I think that just having more powerful cards like the Conduit helps alleviate this, alongside all the other ways to get lands into the graveyard
Almost every black deck in Modern plays Thoughtseize in some capacity, and without it, the format would be much worse-off