It is easier to work with people when you've met in person as well, but remote works if you put in extra effort to make sure that everyone is up to speed. I also forgot to mention that we to meet up with other team members once every couple of months, and that helps too.
The standup meetings ensure that everyone on the team gets to share what they're working on and if they need some assistance every day, and Donut calls provide a good way to get to know people better and be more aware of what everyone is working on - that way it's easier to approach a person if you could use their help on a project.
We've only started having more remote people about half a year ago, so not an expert, but a great way we've used to tackle the absence of water cooler conversations is using Donut - it's a Slack app that regularly pairs up random team members for one-hour chats. It's a great way for getting to know people you might not work with directly and improve collaboration. We also have daily standup meetings and weekly meetings without a specific agenda (the agenda fills up as a week goes by, and it's sometimes good to just chat and connect too). Hope that helps :)