There is a large overlap of mathematical techniques between cond-mat and high energy physics. This has led some to speculate that particles are just excitations

There is a large overlap of mathematical techniques between cond-mat and high energy physics. This has led some to speculate that particles are just excitations in some deeper "condensed matter" substrate. Overall I find Hossenfelder's attitude to be far too negative. I'm fine with canning the big particle accelerators, but apart from that, there is a huge amount of exciting research going on in physics, theoretical physics (not just high energy stuff!), and mathematics.