I really like the MathMajor channel too but for the moment it's very Abstract Algebra centric. For those of you who speak French I can also recommend https://m.youtube.com/@MathsAdultes with videos made by a teacher whose students are future Maths teachers and cover a broad variety of topics like Series, Number theory, Measure theory (from Lebesgue to the dominated converge theroem),... The latest videos are about Topology.