Placement Matches Inquiry

So, after playing all of my provisional matches, I got bronze IV. I went 7-3 and got bronze 4 simply because i was bronze last season? It's honestly ridiculous that I should end up WORSE than last season's placement (bronze 3) winning 5 more matches. Is the system broken? I really want to know because I feel like the current algorithm isn't doing its job correctly.

I know I used to be very bad but I've improved a lot, and I showed that in my matches. I got more cs, didn't feed, and made intelligent plays around objectives. But I got a lower placement than the last season and it's unbelievably disheartening that riot would do this to me even though I've put so much into the game. I'm honestly shocked, I feel like I at least deserve better than bronze 4 when I mainly play with silver/gold level players in normals. If anyone feels the same let me know, I want to know if this just happened to me or if this is truly an issue.