While Ratchet Bomb isnt a Modern staple, it does see play, often in colorless decks lacking removal options, as a Karn, the Great Creator tutor target or in mono-colored decks that cant easily power up Engineered Explosives as an answer to Urza's Saga tokens
Searching up your key combo pieces is great, and the untap effect can provide a burst of mana or an extra Agathas Soul Cauldron activation as needed
Add in a few flicker effects to reuse your best ETB triggers once you get going, and your opponents wont know what hit them until its too late
Watch your opponents creatures carefully and try to bait this out if you can
These are the places where Magic actually gets played, and buying from/selling to stores helps them thrive and keep a community for the game going
When tutoring cards with Sisay, Weatherlight Captain, you need to consider which shrine you need for what situation