What are your thoughts on employee engagement activities? Do they really help/motivate?

At times, yes!

What do you mean by employee engagement activities? Are these extracurricular activities like happy hour or team bonding workshops?

I guess this is helpful because it moves your very formal connection with colleagues into a more human one. It doesn't mean that you'll have to become besties with your team, but more empathy means better teamwork; a better understanding of each other's straights and weaknesses; also more context on a person's life can help with planning their tasks, timings etc.