Most of the ones that pop up on Meetup for me (and I'm referring to hiking groups, not running groups, I can't run for very long at all) seem to pick trail routes that will be at least 5-8 miles long, and you risk getting lost if you have to stop early, or they insist on a specific fast pace in the description, or it's an hour drive away just to get there, or they're in the middle of the day on a weekday, which I pretty much can't ever do.
Pretty rare I find one of these that are both around 3 miles (about my limit most days unless I'm at a park all day with breaks, my feet and sometimes lower back start getting pretty sore) and a more casual pace. I do attend those that I find, though. But that tends to be like 3 per year. Kind of defeats the purpose of making friends in these groups.
I don't think I've found any that are just 'go as far as you want and we'll meet you back at the local Starbucks' though, at least not near me.
Here's the next few upcoming, as an example:
"6 mile Hike Not a Beginner's hike" - (Tuesday midday)
"About 4.5- or 5-miles total" - (Tuesday midday)
"Walk about 2 miles" (but Tuesday midday and 45 minutes away, can't drive there, hike 2 miles, and drive back during a workday)
"We will be hiking 4.5 miles at a faster pace (3.75 mph) dependent on trail conditions." - (Evening, but fast pace and a bit too long)
"6.5 miles with shorter options" - (from the map it looks like the shorter option is "turn back around", it's one big loop. it's on a Sunday but it's also over an hour drive away from me)
No mention of meeting anywhere afterwards in any of those.