If you are satisfied with the service you are currently using for swapping bitcoin to fiat and you don't think it's expensive or burdensome, then I don't see a reason to change. Keep in mind though. You began your post by mentioning KYC and taxes. The exchange you are using to send fiat to your bank account has your KYC data already and every time you swap crypto to fiat and send it to your bank account, you are creating a taxable event. Your bank most probably knows where the money comes from. They could ask you for the source of funds and/or send information about you to your local tax office. Banks are required to do that. I don't know where you live and what kind of setup you are using.

Because you mentioned that you are cheap, you could compare the fees and see what's best for your use case.