I don't know how your monitor is this efficient, mine consumes around that exact amount (40 watts) according to "displayspecifications.com".

Anyways, with my laptop eDP panel instead (driven by sway), external keyboard, external mouse, I have running:

• systemd, glibc, NetworkManager, all that evil ass background crap
• mpv playing a .ogg to headphones
• Firefox with this website, typing rn
• weechat connected to 3 servers
• toxic
• claws mail
• Tor daemon
• Wi-Fi through 2 walls

Let's look at upower -d:

energy:              35,926 Wh
energy-empty:        0 Wh
energy-full:         35,926 Wh
energy-full-design:  53,049 Wh
(...)
energy-rate:         5,64 W
time to empty:       6,3 hours
(...)
capacity:            67,7223%
technology:          lithium-ion

roflmao (no, I don't know why my battery is already this dead, or at least is counted as such)

EDIT: before anyone mentions how a laptop is cheating, mini PCs all have laptop CPUs/APUs anyway