I will give them 10 years maximum to either shut down or get acquired by private equity at a lesser valuation or even less than 10 years if Clubhouse and their VCs decide to do a down-round due to their ridiculous and unjustifiable valuation. [0]
Twitter released their Clubhouse clone, Spaces. Serves essentially the same function, but is native to Twitter so one less app to download. Hosts have incentive to use Spaces because Twitter allows accounts with larger followings to charge admission to Spaces.
Clubhouse could be at feature parity now, but for existing Twitter users, there's very little reason to start replicating their networks on Clubhouse.
Which ever comes first.
[0] https://news.ycombinator.com/item?id=25883362