It might be both, because some governments have legalized bitcoin and have begun to utilize it as a payment method or currency. However, in nations where it has not yet been legalized, it might be a currency if it is used as a payment method. It might also be an asset because many people are investing in it and profiting from it. If it has a high value, you can call it an asset.
In my opinion, value doesnt translate to if its an asset or not, look at cardano, its not past $4, but it is totally an asset. Same thing with penny stocks, even if the value is very low, they are still an asset. What the price is now doesnt reflect what the price will be in the future.
Back to the original topic, I think bitcoin can be used for both, it just depends on what you use it as. Personally, I just hold my bitcoin, but whenever I want to buy something with crypto, I use a coin other than bitcoin because of the high transaction fees of bitcoin. But to other people its just as much a currency as it is an asset, thats the beauty of crypto, it doesnt have just one purpose, it just suits the needs of the people whenever it is needed. Some people use it as just currency, some people see it as an asset, and some people see it as both. It just up to you what you do with it!