Downtime doesn't have shit to do with slow progression, other than it's the shittiest way to achieve it. Here's a fucking genius idea for you, you can only gain xp for 15mins a day. Isn't that perfect? Means it can take 2years to get to max level, and you can do other stuff instead of having to play a video game, awesome!
Forcing players to not play the game as a timesink is a fucking awful feature. You can have slow leveling without having long downtime in the middle of it, you just you know, tune the fucking xp rate. You can have slow pacing without having downtime, add slower more impactful combat, strategy and whatever else. You can even have an easy way to take pauses(short content sessions with waypoints to pick up where you stopped) without forcing people to take pauses.
Downtime is fine in small quantity and/or as a punishment mechanic. You didn't play well this fight, took too much dmg, now you're going to have to sit on your ass to regen. Next time you can do better and have less downtime. Downtime as a consistent result of whatever you do is fucking terrible.
Downtime also doesn't create a socializing aspect. The rest of your design does. Slow leveling, hard content, group reliant content, that kind of shit forces you to communicate and socialize with people. Take an easy example, force downtime on a wow dungeon. Do you feel like people would suddenly talk to each other? Fucking no, they'd either avoid the content that has the forced downtime because it's not efficient, or if it's the most efficient, they'd alt tab/go afk because there is nothing to talk about when you're facerolling content with any combination of drooling retards. You actually see that when you do hard content even in modern mmos, where you wipe on a boss then discuss how to approach the next fight before you pull again. This isn't downtime, you can pull right away, but instead you choose to discuss tactics and strategy because the other aspects of the game push you to, by having challenging group content.
