The short version
I grew up on these feeds. Not as a marketer at first — just as someone who spent a lot of time watching what made a thumb stop, and eventually got curious about why. That turned into running my first campaigns, then into four years of doing it for other people's money.
What I've learned in that time is unglamorous: most ad accounts aren't failing because of targeting or budget. They're failing because nobody is paying attention week to week, and because the business is measuring the wrong number. An account full of ₹40 leads that never answer the phone is worse than half as many at ₹120.
So I work small and close. I'd rather run a handful of accounts properly than a stack of them badly. You get me in your ad manager, not a junior working through a checklist between four other clients.