Something in my apartment is consuming a ton of power and I don't know what. I would love a graph with a resolution better than a day.
Long term tracking usage of individual device energy usage is nice, but just knowing from past measurements how much a device tends to use is already very useful.
Either ESPhome- or Tasmota-based plugs are great if you want fully local control (e.g. Athom, LocalBytes), or Shelly for local-first control with an option of connecting to their cloud.
Mostly everything else will lock you into the manufacturer's app & cloud. Zigbee is fully local too, but it requires additional hardware.
You can buy a power meter plug - that sits between appliance and socket - and work your way around almost all your appliances apart from, typically, oven, air conditioner(s), and hot water systems. For those you're going to need to experiment by turning as many things off as you can, to establish a baseline, and review your switch meter periodically for short (several minute) intervals, with and without the larger appliances turned on.
(You can get induction coil systems to report usage of these larger appliances, but they're typically onerously priced.)
Or hire an electrician to do it, if you aren't totally confident in your ability to do that safely.
Entirely reasonable to be quite afraid of it - it’s a good way to get killed if you aren’t very experienced around somewhat high voltages (240v).