In light of the upcoming Trade Deal between the Indians and the EU: Why were the Chinese allowed to trade without as many tariffs but not the Indians?

I'm citing below details a out the India and the European Union which are set to finalize a landmark free trade agreement later this month.

Here are my questions:

• Why did they have tariffs in the first place, and why did the EU have to wait for Trump to bully them in order to do trade with the Indians? Global trade seems to me like a popularity contest for some reason, and some nations are "cool" and some are ostracized.
• Why do the Indians need to protect their agricultural sector if they're able to make things so cheaply? That's sort of like Saudi Arabia somehow protecting its oil industry by boycotting outside oil into their nation (which to be fair, I'm not sure that they do or not do). I don't see a scenario of the Indian people buying EU agriculture given the price differential, the cost of transportation, and also the quality after traveling 8,000 miles or so.
• If the EU agriculture is able to produce some items cheaper than what the Indians are doing, then why should the Indians charge a tariff on that?
• How much of a bump to GDP would this mean for India?
• Why were the Chinese allowed to trade without as many tariffs but not the Indians?

Key Aspects of the Deal:
Goods: Reduced tariffs on Indian exports (pharma, textiles, engineering) and EU goods (machinery, tech).
Services: Easier market access for India's IT, consulting, and financial services.
Investment: Encourages FDI, technology transfer, and job creation in India.
Digital Trade: Includes provisions for e-commerce, data flow, and intellectual property.
Exclusions: Sensitive agricultural and dairy sectors are off the table for India.