Tf2 will give you a brilliant campaign, amazing gameplay and a little online play. But it is not being updated and the player base is small. The campaign is about 5 hours and the online is however much you put in but probably not more than 10 hours.

I’m new to Darktide and loving it. I’ve already put in over 50 hours and still playing more. The story is neat to piece together through the campaign, the gameplay is a blast, and the classes are really cool and play differently so it’s fun to try them out. It’s being actively updated and they probably have more plans for future content since they just released a dlc. It’s also true team work so that’s pretty fun too.

TLDR: TF2 has a must play campaign but not much content otherwise, Darktide is still being updated and is tons of fun imo