Well there is A value to it. How much value is up to the free market. There is no revenue, balnce sheet, dividends, but there are some fundamentals that you can look at and point to increasing value. For starters, the bitcoin network is enormous and complex. There is no single entity that leads it, and it is only governed by the algorithm. The hashrate in the bitcoin network is at its highest peak. The higher the hash rate, the more secure the network. The bitcoin network has been up 24/7 since the day of its inception more than 10 years ago. The same can't be said about the Federal reserve system. Our banks like to take holidays on weekends. Settlement of funds can take days on banks, when it takes no more than an hour on Bitcoin network. Your bitcoin can never be debased by infinite printing, apart from what is set in the algorithm to a maximum of 21 million, same cannot be said about fiat. Bitcoin has also survived 10 years + and keeps on going higher, that adds faith into the system.
Bitcoin does something much better than being "put in a mattress". More importantly, the fact that you can't touch it makes it the most unique store of value. One mind blowing idea is that you can technically store Bitcoin in your own brain, and no entity on the planet will ever be able to touch it. What I mean is that if you memorize all 24 smart phrase keys, and then wipe out any hardware wallets or paper records of those smart keys, no one on the planet can access that value stored on your bitcoin wallet except you, and you can do that with billions of dollars worth of bitcoin. I am not aware of any single asset out there that can do that.
Of course, it probably is not advisable for you to tie so much value to your memory, because if you forget the order of the smart phrases, that bitcoin is gone forever.
Again I look at it as another hedge/ asset that you can diversify anywhere between 1-10% of your portfolio depending on your appetite for risk. I am bullish on its future, but it is easy to go down that rabbit hole and hold the bags for years in a bear market.