It turns out there are real performance benefits to working out with a buddy. But aside from motivation from moral support and distracting you from the pain, those improvements can also come from another interesting source: insecurity.
If you don’t know your limit, the Köhler effect can really mess up your workout. I’ve seen a lot of people burn themselves out trying to keep up with a group they should not be. I’m not a good runner, but I see it when swimming and cycling.
I met someone last year whose strategy was to go with the fastest group, and try to hang on with the hope that there’d be improvement as time went on. This person was so used up, they couldn’t hang onto the second fastest group. I don’t know if they made the third… It was ambitious, and there are some for whom that would work. There’s value in trying to see if you can, but have an exit strategy in case it’s too much. It might not be today that you fit with that group, and it’s fine to take it down a notch for a speed/distance/etc that you can in order to get stronger.