The Bhagavad Gita is at the very least 8000 years older than the Hare Krishna movement, which is a modern piece of shit, not an ancient one.
As for its teachings, it's a mix of "we don't take these literally, as they do, but rather as allegories", "they have reframed things and likely poisoned the well in your mind by assigning meaning to the quotes and framing them in a certain way", "they purposely mistranslate things to force in concepts like sin", "most of these writings are at least somewhat corrupted over time" and "some mythologies will only make sense fully once one has a certain level of advancement to perceive them".
Meditate on each of these reasons.
This is actually very opposite to reality, and the ISKCON cult leaders know this. The quote that is used to justify this belief is not talking about the Kali Yuga, but the Treta Yuga.
In Kali Yuga, it is actually much more important to have personal power, and "rebelliously seeking enlightenment rather than accepting the mainstream traditions" is actually the optimal path to advance. Any actual Hindu Sadhakas (a term those who do direct Theurgy with the Hindu Gods rather than just attending temple and other average things) with some spiritual experience will tell you, as I've personally heard many of them correct this Bhagavad Gita misconception.
Yes, because it is a cult led by people who are a mix of absolute scammer and idiot misguided by the Enemy. "Krishna" was a spiritual concept, an aspect of a deity that is supposed to teach a specific lesson about a specific occult principle within the framework, not to be taken literally and absolutely not to be considered some Supreme God, as even most regular Hindus, let alone Sadhakas, let alone ToZ members, would tell you that that is retarded.
The issue really isn't that complex. Many "Hellenists" and "Norse Heathens" on tiktok just sing in the forest, pray to Aphrodite for beauty, and set aside bowls of fruit and bread for the Gods, which is absolutely not what these mythologies were trying to teach, because these people aren't smart enough to see things critically, and simply keep their low-level beliefs about Divinity but with a new coat of paint. Similarly so, many Hindus are driven into this cult because of the inherent corruption within Hinduism itself (much less than in Hare Krishna, but still present).
We go beyond that, understanding what these mythologies and religions were actually trying to teach: allegorical messages about the true Gods, to be understood in layers, and to expose individuals to symbols and knowledge that would help them advance according to their level and culture.