Mene kuch din pehle ek news padhi aur video bhi dekha tha ki overseas mai ek sheher hai jahan ke logone 100 dolphins qatl kar diya sirf religion ke naam par aur phir mujhe laga ki hum bhi toh yahi karte hain. Goats ko kaat dete hain woh bhi masoom hi hai, bezubaan kuch jaanwaron ka thik hai magar yeh toh bohat saare hote hain na. Aap isse mujhe samjhaiye aur bataiye ki bakra-eid mai zibha karna wajib h ya mai woh paisa donate kar sakta hu?

In Islam there are are only few animals who’s meat is halal. And if you see these all animals are grass eaters it means they are directly related to the nature but those group of animals who eat other animals are not in the list of halal animals. It shows that Islam wants to maintain the gap ie no doubt for us human eating vegetables is more suitable and beneficial than meat but even if it has allowed to eat meat only those animals and birds are allowed they consume direct from the nature.
Now if we talk about why we eat meat and why do we slaughter innocent animals, long story short, Allah is our creator and He knows better that why he has created all these animals and what is their exact use. But as today’s biology says about the food chain it means their one of the important use is that they has to consumed by another group of the food chain.
What you said about Dolphins, Islam doesn’t allow to eat those animals either if their generation goes very slow or if they are beasts or their meat is not suitable for human body.
About Qurbani if you are still in this 21 century their are millions of people who do not have food to eat so if we use Qurbani animals in a proper way we can feed millions. Also giving Qurbani brings many blessings that you can find in many traditions of Holy Prophet (s) and Aimmah (a.s).
But Qurbani is only wajib for those who is performing wajib Hajj, other than that it’s Mustahab. But if you want to give money instead doing Qurbani you will get sawab but not equal to the Qurbani. You can feed poor with the same meat.
And don’t think slaughtering halal animal is not good. It’s just rumour otherwise those who say this they kill thousands innocent human daily (specially western regime and people) and consume mostly meat as their food but they only raise their voice for dogs and pets.
In Hindu religion it was not always that they were not eating meat no they were and even today 60% of them they eat meat.
But Islam says don’t kill an ant without reason but as for as food concern yes Allah has created these few halal animals to be consumed by Human.