Because front-end engineers always fall for whatever cult is hyped right now.
They usually don’t understand the issues around the things they want to build, they do it because it’s cool and new, and don’t stop to ask or research anything.
And backend engineers not researching how to properly implement them and completely missing the point, yet arguing and blaming front end devs for being "useless". /sarcasm
On a serious note:
JWTs have use cases, but your company is probably not the one. Nice thing about JWT is that there is no need to query the DB every time a request hits a service. JWTs for session should be short lived and refreshed often. In case you need to invalidate it, you invalidate refresh token and window for attack becomes short. It's not perfect but it's certainly not useless and just the hype.
They usually don’t understand the issues around the things they want to build, they do it because it’s cool and new, and don’t stop to ask or research anything.