[androidmatcha]

In Settings>Developer_Options>Running_Services, I see several things that I don't need.
https://imgur.com/a/YKE8Esg

I believe that unnecessary services that run are unnecessarily depleting my battery, leading to a shorter battery lifespan.

I use my fingerprints to unlock, so I'm not sure if I need these services that I see are on the list of "running services":
★ Face
★ Intelligent Scan
★ Iris

Question 2. Do "cached background processes" sap my battery?

I see the following "cached background processes" https://imgur.com/a/vb9EsuD

Here are some that I don't need:

★ Bluetooth
★ NFC
★ Samsung DeX System UI (My Samsung phone is not connected to an external monitor/computer)
★ Google VR Services (I don't need/use VR)

https://imgur.com/a/vb9EsuD

Running Samsung S9 on Android Pie. (My phone is not rooted and not rootable.)

[Tim1954]

You could also go to settings... Apps... Show system apps...
Here you can go through the many apps one by one and make sure they can't run in the background (battery), and they can't use mobile data in the background (mobile data).
You will be surprised how many things run in the background... I have a marked increase in battery life and the phone is much faster now...

[Rukbat]

Cached means stored in storage, not running, so not using battery.

Face, Intelligent Scan and Iris are part of the biometric services, which includes fingerprint, it's all one package.

Everything you see there but Firefox, Tasker and IFTTT are normal for a Samsung phone - they're in RAM. (And they're needed for normal functioning, or a process in them is needed. [Not every app has every process it needs written into it - that's wasteful. If an app that's always going to be in the phone, like the Tee service, there's no reason to write tee code into every app, just call tee and use the process from it.]) Most of them aren't doing anything, so the amount of battery they all use, in total, is probably the equivalent of needing to be charged 1 minute sooner. (But why are you running Tasker and IFTTT in the same phone? Tasker can probably do anything that IFTTT can do. It's not going to use much more battery, but why have 2 apps that can do the same things?)