nmap - Service Scan scans even closed ports?

Hello, I often use nmap to scan the full port range for both UDP and TCP, and in the same command I tell nmap to do a Service/Version Scan.

So my command looks like this: nmap -sS -sU -A/sV -p 1-65535 -T4 -v

So at first it scans for open/filtered ports, and then for Services. But it seems like it scans all 65535 ports for Services even if it pointed out the open and filtered ones just before.

Initiating Service scan at 00:00

Scanning 65536 services on example.com (0.0.0.0)

So it takes like 3 hours to finish.

Does that make sense? I don't know much about networking but for me it doesn't look like it makes sense at all.

Thank you