Except they already tried to get thousands of votes thrown out. Their sincerity in wishing to overturn election results is not really in question, whether or not they believe the election was actually 'stolen'.
Look, this kind of complacency is how democracies undermine themselves. Democracies the world over, for many decades, have thought themselves immune to authoritarianism, only to slide back into it as a result of complacency and empowering those who would break down the democratic structures.
I haven't even mentioned fascism.
But since you ask, yes, I can point to examples: three counties in Pennsylvania excluded thousands of votes (from Democratic-heavy areas) because the outer envelope lacked a date, even if the ballots were received before election day. The Penn. Supreme Court supported them. It was challenged, and then the SCOTUS vacated the decision because the election had already passed. So thousands of ballots ended up not being reflected in the count.
They pursued similar suits in several other swing states, targeting Democrat-leaning areas.