I had similar problems importing hundreds of VCF contacts into Outlook 2021. Outlook only allows you to import one VCF file at a time, and I found that after the process I was missing details such as email and images. The most reliable solution I found was using the WholeClear VCF to PST Converter. The expert converter allows you to convert VCF to PST files in bulk. It retains every field for contact data; I didn't lose any data with the WholeClear solution. The software works offline on Windows, works with all versions of Outlook including 2021 and 365, and is extremely user-friendly to use. Developed a free demo version for testing.