It's for multiple reasons.

First of, 30mA through the chest is the danger territory. Things can happen before this, but that's generally where it's really dangerous. Dry skin can have 10kOhm resistance or more - so with 110V or 220V it's borderline if you get into the really dangerous territory.

If you get current through an arm, or other body parts, but not through the chest, you'll almost certainly walk away from 220V.

If we jump to a 22kV line, and assume a 10kOhm skin resistance, the current is no longer under 30mA - it's a whopping 2A - well above what's fatal. And it's no longer depositing tens of watts. It's depositing tens of kilowatts. Close to 50kW if we assume a static 10kOhm resistance.

This leads to internal and external burns. Those burns may lead to kidney failure as well. Even if you only get current through a body part other than your chest, you'll have severe burns.

That means the current in the transmission line is less than the current in the household wiring as there using a transformer we decrease the voltage and current is increased to keep the same power.

This is mistaken. The voltage is high to reduce losses, but you don't have a 22kV distribution line to your home. You have it to your neighbourhood. It's not uncommon to have hundreds of amps available at a high voltage line. In addition, the short circuit performance is likely to provide a higher short circuit power than what you receive in your outlets at home, as the impedance in the system is likely to be low.

It's for multiple reasons.

First of, 30 mA through the chest is the danger territory. Things can happen before this, but that's generally where it's really dangerous. Dry skin can have 10 kohm resistance or more - so with 110 V or 220 V it's borderline if you get into the really dangerous territory.

If you get current through an arm, or other body parts, but not through the chest, you'll almost certainly walk away from 220 V.

If we jump to a 22 kV line, and assume a 10 kohm skin resistance, the current is no longer under 30 mA - it's a whopping 2 A - well above what's fatal. And it's no longer depositing tens of watts. It's depositing tens of kilowatts. Close to 50 kW if we assume a static 10 kohm resistance.

This leads to internal and external burns. Those burns may lead to kidney failure as well. Even if you only get current through a body part other than your chest, you'll have severe burns.

That means the current in the transmission line is less than the current in the household wiring as there using a transformer we decrease the voltage and current is increased to keep the same power.

This is mistaken. The voltage is high to reduce losses, but you don't have a 22 kV distribution line to your home. You have it to your neighbourhood. It's not uncommon to have hundreds of amperes available at a high voltage line. In addition, the short circuit performance is likely to provide a higher short circuit power than what you receive in your outlets at home, as the impedance in the system is likely to be low.