If you are looking for the fastest way to split a large VCF file, I can highly recommend trying
Softaken Split vCard Pro because this is specifically designed to effortlessly divide oversized VCF files into multiple parts. The best part of this expert vCard tool is that it supports all versions of the vCard file format, including 2.1, 3.0, and 4.0. Additionally, this offline VCF splitter tool preserves all content field data like names, emails, and company addresses during the splitting. You can seamlessly run this tool on any Windows OS, including Windows 11, and it provides a free trial.