It took Twitter 10 years before it was profitable [1]. I'd guess that Anthropic will be one of the companies left standing when it's all said and done, assuming nothing catastrophic happens.
Also the switching cost. If its negligible theres no reason for Anthropic to be considered a going-concern in the long term. So its valuation makes no sense from a DCF basis unless you are expecting a liquidation in future. But even then, the liquidation value still doesn't justify its valuation today.