Is setcap deprecated?

I'm starting a webserver as non-root using a *systemd* unit file. I am getting listen tcp :80: bind: permission denied even though I already ran setcap cap_net_bind_service=+ep on the executable. In an example unit file on the internet I found CapabilityBoundingSet=CAP_NET_BIND_SERVICE AmbientCapabilities=CAP_NET_BIND_SERVICE to be used in the unit file. So I tried that out, and suddenly the application can bind port 80. What does that tell me? setcap is old/deprecated/ignored? Only by *systemd* or by Linux in general?