MacBook showing battery service required no longer turns on after sleep

I got a MacBook Pro 2016 at the office. It was working great however the battery kept saying it needed to be serviced and wasn't really good at holding charge either. 100% would reach ~60% in 30 mins. But I didn’t mind as I am mostly plugged in anyway.

Then I brought it home, used it and didn’t shut it down but rather clicked the power button (which I presume is standby), closed the lid and put it on the shelf.

In the morning I try to turn it on and nothing! It's not turning on. I kept it charging for hours but still no response. Tried the SMC reset but nothing. I am suspecting it's because of the battery but what are your thoughts?

You know that, at the very least, the battery needs replacing. There could also be a problem with the power unit. However, hardware problems are best diagnosed in the presence of the machine itself. Take it to an Apple Store, or other Apple-authorised technician.

(Unless, when you say you 'got it at the office', it's the property and responsibility of your employer: in which case you should return it to them.)

A technician will be able to confirm what needs doing, and how much it will cost, leaving you to decide whether that's worthwhile. If you got it very cheap from office surplus, then a few hundred dollars (or equivalent) would be worth it, IMO.