They're primarily exciting because they exist at a fringe of research and challenge prevailing biology dogma that specialized organs (specifically the animal kingdom's specialized organs, the nerves) are required for complex behaviors and intelligence. They an extremely important research area for philosophy of mind and their study has only provided more and deeper mysteries.

Slime molds aren't ready-made solutions to practical problems. They're a signposted paradigm shift that indicates we need to re-evaluate some of our a prioris. Alongside advances in understanding complex behaviors in plants, slime molds represent one of the largest challenges to long-standing assumptions we've had for millenia. Unfortunately the response to recorded behaviors of adaptation, memory, learning, problem solving in things without neural structures has hilariously been to shift goal posts and underline said neural structures as a prerequisite to these things being meaningful. Silly things like "super computer slime" and pop science articles drown out the incredibly important experimental observations made about these beautiful organisms, this much I agree with.