This explains why the Gorosei didn’t target Luffy earlier

I get why the Gorosei didn’t target Luffy earlier. That has to do with 3 things: not having information, their objectives and lack of opportunity.

Let’s do a recap.

When Shanks stole the Gomu Gomu no Mi, the World Government probably had a rough idea of the islands Shanks and his crew frequented. However, they didn't possess the manpower or resources to monitor every location effectively. Among these islands, Goa Kingdom presented a unique challenge for surveillance due to the presence of formidable figures like Monkey D. Dragon and Vice Admiral Garp, both of whom had significant influence and power that deterred overt spying operations.

Initially, the World Government had no clue that Luffy had consumed the Gomu Gomu no Mi. This crucial piece of information likely came to light only after the events in Alabasta. The Straw Hat Pirates’ exploits in Alabasta, where they defeated the Warlord Crocodile, brought Luffy and his crew into the global spotlight. The sudden prominence of Luffy, coupled with his unique abilities, likely led the World Government to realize the significance of the Devil Fruit he possessed.

Post-Alabasta, the World Government faced a dilemma. They could have initiated a manhunt for Luffy or placed an extraordinarily high bounty on his head. However, branding a rookie pirate with a disproportionately high bounty would attract undue attention and raise questions that the Government preferred to avoid. Even the bounty Luffy received after Alabasta seemed to have experienced some delay and potential manipulation, as evidenced by how long it took for the updated bounty posters to reach locations like Jaya.

Sending assassins to eliminate Luffy was another potential strategy, but this too was fraught with complications. Assassination attempts could provoke retaliation from powerful figures like Dragon and Garp, creating significant political and military strife. Moreover, the logistics of tracking and eliminating someone constantly on the move at sea posed a daunting challenge. After Alabasta, Luffy’s journey took him to Skypiea, effectively vanishing from the World Government’s radar. Subsequent locations like Water 7, Thriller Bark, and Sabaody Archipelago saw similar patterns of brief appearances followed by disappearances, often aided by unpredictable factors like the intervention of Bartholomew Kuma.

Marineford represented a chaotic convergence where Luffy’s unexpected arrival added to the turmoil, leaving little opportunity for targeted action against him. The one viable window for the Gorosei to strike might have been at Water 7. However, they prioritized capturing Nico Robin over Luffy. This decision aligns with the Gorosei’s primary objectives: preventing the spread of knowledge about the Ancient Kingdom and safeguarding Imu's position. Robin's ability to read the Poneglyphs posed a direct threat to these goals, making her a more immediate target than Luffy.

By eliminating Robin, the World Government aimed to control the flow of critical historical knowledge, while the secret of the Gomu Gomu no Mi remained secondary. This explains why Robin was kidnapped in Water 7 instead of Luffy. The Gorosei's actions were driven by a calculated strategy to minimize risks and maintain their overarching agenda of suppressing the true history and preventing any potential challenges to their rule.

In the post-time skip era, events unfolded rapidly, leading up to Luffy’s arrival in Wano. This period provided the World Government with a significant opportunity. As the Gorosei themselves acknowledged, if Luffy were to perish in the intense conflict with Yonko like Big Mom and Kaido, it would raise no suspicions. The chaotic environment of Wano, filled with formidable adversaries and unpredictable battles, offered a perfect cover for eliminating Luffy without drawing unwanted attention or backlash.

In conclusion, the World Government’s delayed response in targeting Luffy is understandable. Throughout most of his journey, Luffy remained elusive, and when his location was known, other priorities, like neutralizing Robin, took precedence. Direct action against Luffy often risked provoking powerful figures and raising questions. Therefore, their strategy was to wait for a moment when eliminating Luffy could be seamlessly integrated into the broader chaos of pirate conflicts, thereby avoiding suspicion and achieving their goals with minimal fallout.