These are mostly science and technology related.

Just Have a Think: Energy, electricity, fuels, batteries, renewables

Engineering with Rosie: electricity production, transmission, storage etc.

xkcd’s What If?: physics, silly questions, silly answers

Applied Science: Science, technology, DIY lab stuff

Elina Charatsidou: Nuclear physics

Future Proof Health: anything health related

AlphaPhoenix: Material science, physics, technical stuff

Design Theory: In-depth explanations on why items are designed to look a particular way.