It’s a service worth $40 billion, with a community of tens of millions of daily users. Even if it’s in a downward spiral, I don’t think anything of its size will just quickly die.
Nobody believes that Twitter is worth $40billion today, not even its current owner.
In any case, Twitter was worth as much as $60 billion in early 2021 [0], so we can still say it's been a service valued in the tens of billions. What is the expected timeframe for a declining service in that market cap bracket to "die"? Which examples do you have in mind? Geocities? Myspace?
[0] https://www.financecharts.com/stocks/TWTR/summary/market-cap