No, that doesn’t reflect the situation. Charters enshrine the public school revenue by allocating some of it to “better” schools. They make it harder to lower school district revenue as they (in the eyes of parents) make the established system work better.

That is not the stated goal of charter schools. They openly state private business can do better than government.

That’s different than aiming to reduce district tax levied. I’ve read a variety of statements from charters themselves, including that one. There are also proposals to privatize administration of school districts using the same reasoning. In education, no matter who is speaking, typically the focus is on performance, retaining teachers and meeting more diverse student needs.