I'm sorry maybe my Q or topic didn't contain enough details:
The students question about Bitcoin starts at min 22:24 I think, and it's about what will happen when the mining reward approaches zero.
Tim Roughgarden ended his thoughts by describing it as existential risk for the only way out is if TX fees exceeded mining costs, and TX fees depend on demand curves and other factors not something that  miners can control and determine solely.

I also recalled the Crypto Climate Accord named the year 2040 to achieve net zero carbon footprints from crypto related activities, and I wondered is it just a coincidence or is it because the Bitcoin community nearly do nothing to become more eco-friendly.
So I tried to explore what the other side (Bitcoin community) have to say about that