If your product has no marginal cost (as much software effectively does) then you can justify any P/E with the prospect of increasing sales without increasing opex or capex. Of course that's just an approximation since you will realistically have some kind of customer acquisition cost, some of which is also realized in adding more developers to create features that are adoption-blockers. But still, that scalability is what makes early stage software companies such attractive investments.

I would be much more worried about competition. Video conferencing has a small moat especially since major incumbents are already in the space