Why no built-in TBC in 1980+ VCRs?

[DVtyro]

Originally Posted by ARC Tech-109

A frame store is not a time base corrector and this doesn't necessary imply that they are inclusive to have one or the other.

I know that a frame store is not a time base corrector. I just thought that a storage is the more expensive part of a TBC, and since the VCRs in question have one, then maybe having a TBC would put this storage to a good use. Apparently, I am wrong. Thanks.