Advice on PhD applications

Hi, I'm preparing to apply for PhD programs this winter for a September 2025 start. Even by limiting my scope geographically, there are still a fair number of schools to choose from. Things will obviously start to thin out once acceptances/rejections and funding offers come in, but any advice on filtering the application process itself?

Is the school/program really that important at the PhD level, or is it really more about finding those 1 or 2 professors that you'd really like to work with?

TIA