18.000 is heavily influenced by all the people driving >100.000 km per year, unless that's the median, not the average. I'm far below 10.000 and still waiting for it to be worth it for me. I'll calculate with 10.000 for now.
Modern ICE cars need far less than 6l. A modern VW Golf for example only needs 4-5 l per 100 km (4.5 avg, and yes it actually is that low, I've been driving a modern VW Golf at the military a few times and have tracked my average fuel consumption there).
Gas currently fluctuates from 1.525 to 1.599 in my area, so I'm always only filling the car on Monday mornings when it's 1.525.
10 000 * 1.525 * 4.5/100 = 686.25€ per year.
Even if there's a major crisis like when the war in Ukraine started and the price goes up to 2€ per liter for some time and I'm at 1.8€ average for the year (I have never had such a high average so this is really stretching it), we get 10 000 * 1.8 * 4.5/100 = 810€ per year. Worst case, never happened before scenario.
Economic modern EV need ~16 kWh per 100 km. The average price per kWh at home is 0.2€ in my area.
10 000 * 0.2 * 20/100 = 400€ per year.
= 286.25€ (410€ worst case) per year saved (purely for moving the car), assuming I always charge at home. If I do longer trips on holidays and have to charge somewhere else that gap gets lower.
Even when adding less taxes, less repairs (but modern engines really don't need much repairing, even though they're much more complex than electric motors and wasting more energy) it will still will take a long time to break equal (probably never because I need a new battery before breaking equal).
If I have an average of 10k km per year that's 16.200€ for 200.000 km over 20 years with an ICE car at 1.8€/l (higher average than I've ever experienced) or 6.400€ for the same with an electric car at 0.2€/kWh (which is below my average of the last two years). Ignoring inflation for simplicity, just assume my salary goes up with inflation so percentually it stays the same.
If I need a new battery (10.000€, actually more but I'll just say 10.000 for now since they'll likely go down at some point) every 10 years then I'm just about to break equal after 20 years, right before going negative again by buying another battery.