This is exactly what they want. Oh if you are so worried about it, just vote in person. The stats are clear on what happens here. Your comment on the internet doesn't make up for the huge decline in voter turnout if you take away mail in voting and in person voting leans strongly in favor of the American fascist party.
A fuck it, I'll just vote in person attitude will never generalize beyond the strong statistical favor of the fascists. It's not the right answer. The answer is fight, fight fight. Protest outside your post office. Write your local representatives about your concerns. Be a polite asshole in the post office and demand your mail gets marked. Not just your mail in ballot. Do it with a letter to your grandmother or a vulgar postcard to your landlord.
Don't roll over on this.