But still, nothing is lost - at the contrary there are reasons to be optimistic.
One of the biggest indicators that the "currency" usage could come back eventually is the adoption of the Lightning Network. It grew very steeply in 2021, now it grows slower but still steadily and much more pronounced than before 2021.
Lightning adoption is bullish for two reasons. First because the main use case is trading goods and services, and not hoarding (for hoarding, on-chain txs are better/safer), and second, because value is frozen in LN channels. These Bitcoins can of course be unfrozen but they will probably stay there longer than in a "normal" UTXO and thus unavailable to "hoard and sell" speculation.
Then there is the movement of states adopting it as legal tender, with El Salvador, which also should boost "currency" usage.
There is also no reason to "not" spend Bitcoins if you think it will go up more. Simply spend it and re-buy, you will be strengthening its ecosystem and network effect.
The best case scenario would be that Lightning/currency usage would continue to rise and eventually (most likely in a couple of years, not in 2022) become the main use case for Bitcoin again. Speculation will always exist, but if currency usage increases, this should result in a more stable price, even more so if eventually "fixed prices in Bitcoin" become a thing so you can anchor the value of a BTC to certain goods or services.
So a virtuous cycle could evolve: Bitcoin becomes more stable but still attractive as an investment, and as it stabilizes, it becomes also gradually more usable as a currency.
Well lightning network is different than bitcoin its not to put a coin in the franky box, but its much more complicated than bitcoin, bitcoin is fundementally simple, 3 people in the world can install a node, and they will be able to run the network, have an address, mine it and make paiment in a secure manner. Nobody needs to be tech savy, have any preeixisting fund, nothing needs to be locked or anything. And you could have roughly the same functionality with an spv wallet or such.
Plus LN wouldnt change much to the problem of volatlity and speculation games.
And i dont think the "scaling problem" is the issue at least for e commerce a delay of even 1h is still mangeable, even paypal can have similar delay. Its not likely the order is going to be processed in the minute on an online platform and some internal token can be used with bulk paiment if you really want to attract compulsive buyers. I dont think its really the deal breaker here.
For real shops maybe more and still there is also an old thread where satoshi talked about the soda machine where this kind of problem is issued. The vendor could check on the main's mining pool to see if the transaction is in their memory pool, in theory there should be relatively safe way to prevent double spend and work around confirmation time, especially for small paiments.