There’s a reason Chrome was able to steal the alt browser market from Mozilla at a time when even laymen understood that IE was awful - Mozilla stopped innovating the second they were winning. They had tabs! What more could you want?
That’s part of the story, but even more important is that they shoved it down everyone’s throat.
At the time most Americans were farmers. Can’t be Sunday because it’s a Christian rest day, Wednesday neither because that’s market day. They might have to travel a whole day to get there, so it can’t be on Monday or Thursday either. Which leaves only Tuesday, Friday and Saturday.