I don't think there's a single person in the SEO industry that doesn't owe a debt of gratitude to Matt in one way or another.
His polished presentations, humor and controlled candor were latched on to and dissected by virtually everyone. Sure, he couldn't always tell us what we wanted to know but what he did say could be trusted, even when what you had to hear were the words he was holding back.
For those who may have joined the ranks after Matt departed, I wrote a three-part retrospective for Search Engine Watch back in 2014 (https://searchenginewatch.com/sew/opinion/2339368/googles-matt-cutts-on-seo-a-retrospective-2000-2005) that highlights some of the most important contributions Matt made to Google and the industry.
Spoiler alert - they are vast.
While John, Gary and Danny are doing fine jobs (seems it takes three people to replace Matt ;) ) I can't think of anyone who doesn't wish to sit down at their computer in the morning to discover a new Cutts video with some great advice for webmasters like: