It's mostly for use cases where you can lose physical access to the computer like overnight at the office, at a hotel while travelling, in a shared server room, etc. It's extra assurance that the computer runs the software you expect it to run and nothing else without at least being somewhat noisy about it.
This can in turn be used to use the TPM to get a disk encryption key, so you can do full disk encryption but still boot to a normal login screen without entering a password. It will only hand out the key with the correct signed boot chain.
If you have a desktop PC at home that nobody untrusted touches, then yeah there isn't that much value to it for you.