First, LTSB requires an Enterprise license, which most corporations haven't traditionally sprung for. (It actually costs a little more than Enterprise, actually.) Microsoft seems to be trying to pressure corporations into it, but most businesses use the Pro licenses that come with their PCs, which has traditionally been more than adequate.

Second, LTSB is not really intended for general desktop use, even in a corporate environment. LTSB is intended for devices like MRI machines and the like which need Windows, and the latest security updates, but literally no improvements whatsoever otherwise.

Ideally, corporate users should remain roughly one major Windows 10 release behind the current one, but of course, three times in the last six months, Microsoft has broken the updater and updated PCs to the latest build despite group policy prohibiting it.