I know this is a troll post, but what even do you define as "the first EVs"? The electric Studebaker, ca 1902? Electrovair (1966)? EV1 (1996)? Tesla Roadster (2008)?

Prior to the switch to lithium, the batteries were mostly lead-acid, and you would be correct. They were terrible, and that's a big part of why EVs didn't catch on. But post-lithium, I'd say everything newer than ~2012, the high-voltage pack is likely to outlast the rest of the vehicle. But if you did replace the pack, current prices are around $8k for a new, unused pack for a typical EV. And the low-voltage battery (lead acid/AGM) still exists in an EV, serves a similar purpose, and fails at a similar rate.

Real world battery health (I.e. wear on the high voltage battery) is typically around 85-90% health remaining at 100k miles.