The battery pack is easily dropped in a Tesla, but you should expect it to last the life of the vehicle (at least 500k miles, almost 25 years at 20k miles/year of driving).
Data is based on cost of electricity versus cost of gasoline. EVs have only a handful of moving parts compared to internal combustion vehicles, so maintenance is less overall (battery coolant and brake fluid changes ever 2-4 years, cabin air filter every 1-2 years, tire rotations every ~6k-7.5k miles).
The US is a bit dysfunctional compared to Europe (where they put a priority on shifting away from fossil fuels with subsidies and taxes); regardless, even a Tesla Model 3 without federal incentives (which finish phasing out for Tesla shortly) is still cost competitive when total cost of ownership is evaluated against most internal combustion vehicles (except hybrids).