I'm currently reading Grey Lensman, a pulp SF serial from the late thirties. The pacing is miserable, everything goes too fast and the characters either barely exist, are paragons of virtue or are completely evil, no in between. I'm reading it more because it was influential than because I enjoy it even though it does have it's moments.

Compare that to a book I read earlier this year, A Memory Called Empire, published in 2019 which had brilliant pacing great characters and character development and a great plot.

You're just not picking good recent books and are picking good old books. It's not a trend in modern writing, just bad luck on your part.