I can’t think of any. The current oil reserve is supposed to be used in the case of another oil embargo. But its actual use is to lower gas prices when the administration in power needs a political win.
I actually think the purpose of a Bitcoin reserve is to temporarily increase the price so tech-bros (re: Elon) can sell at a massive profit. Then buy back at a much lower price. It’s just a way to indirectly transfer federal dollars into administration pockets.
I can’t find any reason for the government to buy crypto and hold it in reserve.
The only real benefit I can see would be to have the ability to suddenly crash the market on demand. This might be an interesting way to temporarily disrupt states trying to evade sanctions with crypto, but probably not a great investment on the $ to impact scale.