A lot of Democrats agree with you.
Clinton’s emergence will be of little benefit for those who wish to unseat Trump, in fact, it will likely have the opposite effect.
Her nasty fight with Gabbard splits Democrats into Interventionist/Warmonger versus Isolationist/Russian Asset factions and raises the specter of a new Establishment brand of McCarthyism. Meanwhile Trump is being attacked (or receiving lots of free publicity, depending on how you see it) for pulling a few hundred troops out of parts of Syria.
Clinton’s testing of the waters diminishes the stature of all the current crop of Democrat contenders. She acts as if she can merely declare herself in the race and they will all bow and step aside to make way for her. Yet none of them relishes taking her on and criticizing her for fear of making an argument that sounds like a Trump attack. How many Bernie and Warren supporters stay home if she is the nominee?
Clinton’s candidacy puts the Democrat Party focus for 2020 squarely on vindicating her campaign of 2016. Most independents are sick of relitigating 2016 and really really sick of Clinton’s sore loser excuses.