Who decided that a critical battery warning should appear at 7% with no charger nearby?

Windows controls this, and you can change it yourself. The battery levels (low, critical, and what happens at each) are part of your power plan, and the defaults are around 10% for low and 5% for critical, though some laptop makers set their own. The easy way to change them is in the classic Power Options:

• Press Win+R, type powercfg.cpl and press Enter, then click Change plan settings next to your active plan, then Change advanced power settings.
• Open Battery and set Low battery level and Critical battery level. Set them separately for On battery and Plugged in. For example, 25% for low and 15% for critical gives you more time.
• Set Low battery action and Critical battery action to what you want (Do nothing, Sleep, Hibernate or Shut down). Hibernate on critical is a good safe choice because it saves your work.
• Click Apply.

If you prefer the command line, run this in Terminal: powercfg /setdcvalueindex SCHEME_CURRENT SUB_BATTERY BATLEVELCRIT 15 and then powercfg /setactive SCHEME_CURRENT. Use BATLEVELLOW for the low warning. Some laptops hide the battery section or reset it after a BIOS or driver update, so if the values do not stick, check that the manufacturer's power app is not overriding them.