It can take a long time for a lawsuit to actually happen. There's a lot of ways to drag out negotiations over a patent and it can be a while before both parties can't come to an agreement, resulting in a suit being filed.
To be fair, Kearns did represent himself for most of that legal battle. I sure the cases would have been settled much more quickly had he been backed by MIT's lawyers.
Clearly, without this invention, wipers to this day would still work on a sigle speed, calibrated for heavy rain. Millions of tons of wasted rubber and plastic, etc.
"Someone would've eventually invented this" can be said about everything we use. Someone would've figured out the Internet, internal combustion, flying, etc. That doesn't mean it's not a notable accomplishment to do so.
