I have a Surface Pro 4 (I think from 2015) and the battery life now is awful. I might be able to get an hour or two depending on the performance mode, I usually just plug it in while using it now. If I forget to plug it in between uses, it will definitely be dead the next time I go to use it.

Plus it's starting to feel pretty slow. I do still have Windows on it, perhaps installing Linux would help make it faster but it sounds like it takes some work to get everything working properly so I haven't bothered.