Please specify what version of the library you are using: [ 1.2.5 ]
Please specify what version(s) of SharePoint you are targeting: [ SP 2013 ]
I am getting all field values of a list item using below method:
pnp.sp.web.lists.getByTitle(libName).items.getById(8).get().then((item) => {
console.log(item);
});
The returned object contains the look up id for Managed metadata fields instead of the label name. This is a longstanding issue with SharePoint REST endpoint which Microsoft has not fixed yet but there are some workarounds to this problem.

Workarounds are discussed over this StackExchange post.
Hi @unnieayilliath,
Unfortunately, it can't be fixed in the library. This is REST API behavior. But you can leave a user voice for it here.
As a workaround renderListData (works for SP 2013) or renderListDataAsStream (SP 2016+) methods can be used.
@koltyakov Thanks for pointing me to renderListData , I had already up-voted the user voice , but it's been years idk why this can't be fixed at REST API
Going to close this as answered. If the conversation needs to continue please _reopen_ the issue so we can assist. Thanks!
Most helpful comment
Hi @unnieayilliath,
Unfortunately, it can't be fixed in the library. This is REST API behavior. But you can leave a user voice for it here.
As a workaround
renderListData(works for SP 2013) orrenderListDataAsStream(SP 2016+) methods can be used.