You can’t assume a Seed round is the cost of building a startup.
Today a MVP (Minimum Viable Product) can be built for pocket change when the founders vote with their own time (have skills to execute). Using open source languages (Python), frameworks (Django, Flask et al) and OS (Ubuntu) helps keep costs to $0. Infrastructure is the only cost I’d flag and with AWS now in OZ region that too is pocket change.
The reason you’d be wanting to raise a seed round (and follow on rounds) is if you need fuel on the fire and can demonstrate great opportunity. Basically turning your MVP/Product into a Business. The seed capital would go towards business expansion, hiring, more experiments, additional channels, tooling sophistication etc.