Usually, I’d aim for the cloud environments for public resources (serving more than like 20 people), as the traffic won’t be hitting your home network.
Additionally, selfhosting a public service like Lemmy on your home environment probably wouldn’t have the same uptime or reliability, as I only have one strong ISP signal, and no backup generator.
However, pricing wise, selfhosting at home is much cheaper for the processing power you get.
I do, though I run a reverse-proxy (homelab dials out to the proxy, ala cloudflare tunnels, no need for home IP to even be in DNS) using frp in a cloud provider. Hosting critical (to me) things in my lab is just motivation to keep it in good shape.
You are certainly right on cost. I could have bought a (used) server a year for the price of my cloud footprint at peak, though my power bill would probably end up out of control.